diff --git a/csharp/src/AddressBook/Addressbook.cs b/csharp/src/AddressBook/Addressbook.cs
index 5f4a5139e4..b7a08ef042 100644
--- a/csharp/src/AddressBook/Addressbook.cs
+++ b/csharp/src/AddressBook/Addressbook.cs
@@ -160,6 +160,10 @@ namespace Google.Protobuf.Examples.AddressBook {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -330,6 +334,10 @@ namespace Google.Protobuf.Examples.AddressBook {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Number.Length != 0) {
             output.WriteRawTag(10);
@@ -463,6 +471,10 @@ namespace Google.Protobuf.Examples.AddressBook {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       person_.WriteTo(output, _repeated_person_codec);
     }
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/MapUnittestProto3.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/MapUnittestProto3.cs
index 55434c534a..0e261e1b77 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/MapUnittestProto3.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/MapUnittestProto3.cs
@@ -602,6 +602,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       mapInt32Int32_.WriteTo(output, _map_mapInt32Int32_codec);
       mapInt64Int64_.WriteTo(output, _map_mapInt64Int64_codec);
@@ -836,6 +840,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -978,6 +986,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0L) {
             output.WriteRawTag(8);
@@ -1120,6 +1132,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -1262,6 +1278,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0UL) {
             output.WriteRawTag(8);
@@ -1404,6 +1424,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -1546,6 +1570,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0L) {
             output.WriteRawTag(8);
@@ -1688,6 +1716,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(13);
@@ -1830,6 +1862,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0UL) {
             output.WriteRawTag(9);
@@ -1972,6 +2008,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(13);
@@ -2114,6 +2154,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0L) {
             output.WriteRawTag(9);
@@ -2256,6 +2300,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -2398,6 +2446,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -2540,6 +2592,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != false) {
             output.WriteRawTag(8);
@@ -2682,6 +2738,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key.Length != 0) {
             output.WriteRawTag(10);
@@ -2824,6 +2884,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -2966,6 +3030,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -3109,6 +3177,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -3250,6 +3322,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (testMap_ != null) {
         output.WriteRawTag(10);
@@ -3370,6 +3446,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       mapInt32Message_.WriteTo(output, _map_mapInt32Message_codec);
     }
@@ -3493,6 +3573,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -3644,6 +3728,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       map1_.WriteTo(output, _map_map1_codec);
       map2_.WriteTo(output, _map_map2_codec);
@@ -3773,6 +3861,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -3915,6 +4007,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -4216,6 +4312,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       mapInt32Int32_.WriteTo(output, _map_mapInt32Int32_codec);
       mapInt64Int64_.WriteTo(output, _map_mapInt64Int64_codec);
@@ -4436,6 +4536,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -4578,6 +4682,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0L) {
             output.WriteRawTag(8);
@@ -4720,6 +4828,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -4862,6 +4974,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0UL) {
             output.WriteRawTag(8);
@@ -5004,6 +5120,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -5146,6 +5266,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0L) {
             output.WriteRawTag(8);
@@ -5288,6 +5412,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(13);
@@ -5430,6 +5558,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0UL) {
             output.WriteRawTag(9);
@@ -5572,6 +5704,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(13);
@@ -5714,6 +5850,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0L) {
             output.WriteRawTag(9);
@@ -5856,6 +5996,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -5998,6 +6142,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -6140,6 +6288,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != false) {
             output.WriteRawTag(8);
@@ -6282,6 +6434,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -6425,6 +6581,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -6564,6 +6724,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       type_.WriteTo(output, _map_type_codec);
     }
@@ -6691,6 +6855,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
@@ -6830,6 +6998,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       entry_.WriteTo(output, _map_entry_codec);
     }
@@ -6952,6 +7124,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Key != 0) {
             output.WriteRawTag(8);
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportProto3.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportProto3.cs
index d30f22db6e..14c844feae 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportProto3.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportProto3.cs
@@ -124,6 +124,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (D != 0) {
         output.WriteRawTag(8);
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportPublicProto3.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportPublicProto3.cs
index 5aa03a641a..b8c62bc9a9 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportPublicProto3.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestImportPublicProto3.cs
@@ -109,6 +109,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (E != 0) {
         output.WriteRawTag(8);
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestIssues.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestIssues.cs
index 0e409c8b72..59c551dc1b 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestIssues.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestIssues.cs
@@ -148,6 +148,10 @@ namespace UnitTest.Issues.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
@@ -237,6 +241,10 @@ namespace UnitTest.Issues.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
         }
 
@@ -326,6 +334,10 @@ namespace UnitTest.Issues.TestProtos {
               return hash;
             }
 
+            public override string ToString() {
+              return pb::JsonFormatter.Default.Format(this);
+            }
+
             public void WriteTo(pb::CodedOutputStream output) {
             }
 
@@ -459,6 +471,10 @@ namespace UnitTest.Issues.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Value != global::UnitTest.Issues.TestProtos.NegativeEnum.NEGATIVE_ENUM_ZERO) {
         output.WriteRawTag(8);
@@ -577,6 +593,10 @@ namespace UnitTest.Issues.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
@@ -746,6 +766,10 @@ namespace UnitTest.Issues.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (PrimitiveValue != 0) {
         output.WriteRawTag(8);
@@ -918,6 +942,10 @@ namespace UnitTest.Issues.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Item != 0) {
         output.WriteRawTag(8);
diff --git a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestProto3.cs b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestProto3.cs
index d2437bf4b7..0e63e1d6f9 100644
--- a/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestProto3.cs
+++ b/csharp/src/ProtocolBuffers.Test/TestProtos/UnittestProto3.cs
@@ -1019,6 +1019,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (SingleInt32 != 0) {
         output.WriteRawTag(8);
@@ -1695,6 +1699,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Bb != 0) {
             output.WriteRawTag(8);
@@ -1842,6 +1850,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (child_ != null) {
         output.WriteRawTag(10);
@@ -1991,6 +2003,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (DeprecatedInt32 != 0) {
         output.WriteRawTag(8);
@@ -2106,6 +2122,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (C != 0) {
         output.WriteRawTag(8);
@@ -2208,6 +2228,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
@@ -2310,6 +2334,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (foreignNested_ != null) {
         output.WriteRawTag(10);
@@ -2444,6 +2472,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (A != 0) {
         output.WriteRawTag(8);
@@ -2587,6 +2619,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (a_ != null) {
         output.WriteRawTag(10);
@@ -2723,6 +2759,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (bb_ != null) {
         output.WriteRawTag(10);
@@ -2858,6 +2898,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (a_ != null) {
         output.WriteRawTag(10);
@@ -3080,6 +3124,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (PrimitiveField != 0) {
         output.WriteRawTag(8);
@@ -3313,6 +3361,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (MyInt != 0L) {
         output.WriteRawTag(8);
@@ -3490,6 +3542,10 @@ namespace Google.Protobuf.TestProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Bb != 0) {
             output.WriteRawTag(8);
@@ -3624,6 +3680,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (SparseEnum != global::Google.Protobuf.TestProtos.TestSparseEnum.TEST_SPARSE_ENUM_UNSPECIFIED) {
         output.WriteRawTag(8);
@@ -3739,6 +3799,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Data.Length != 0) {
         output.WriteRawTag(10);
@@ -3853,6 +3917,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       data_.WriteTo(output, _repeated_data_codec);
     }
@@ -3961,6 +4029,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Data.Length != 0) {
         output.WriteRawTag(10);
@@ -4076,6 +4148,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Data.Length != 0) {
         output.WriteRawTag(10);
@@ -4191,6 +4267,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Data != 0) {
         output.WriteRawTag(8);
@@ -4306,6 +4386,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Data != 0) {
         output.WriteRawTag(8);
@@ -4421,6 +4505,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Data != 0L) {
         output.WriteRawTag(8);
@@ -4536,6 +4624,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Data != 0UL) {
         output.WriteRawTag(8);
@@ -4651,6 +4743,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Data != false) {
         output.WriteRawTag(8);
@@ -4820,6 +4916,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (fooCase_ == FooOneofCase.FooInt) {
         output.WriteRawTag(8);
@@ -5125,6 +5225,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       packedInt32_.WriteTo(output, _repeated_packedInt32_codec);
       packedInt64_.WriteTo(output, _repeated_packedInt64_codec);
@@ -5492,6 +5596,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       unpackedInt32_.WriteTo(output, _repeated_unpackedInt32_codec);
       unpackedInt64_.WriteTo(output, _repeated_unpackedInt64_codec);
@@ -5764,6 +5872,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       repeatedFixed32_.WriteTo(output, _repeated_repeatedFixed32_codec);
       repeatedInt32_.WriteTo(output, _repeated_repeatedInt32_codec);
@@ -5913,6 +6025,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (A.Length != 0) {
         output.WriteRawTag(10);
@@ -6015,6 +6131,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
@@ -6103,6 +6223,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
@@ -6191,6 +6315,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
@@ -6279,6 +6407,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
@@ -6367,6 +6499,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
@@ -6455,6 +6591,10 @@ namespace Google.Protobuf.TestProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
     }
 
diff --git a/csharp/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs b/csharp/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
index c87b367a32..a7d1d72628 100644
--- a/csharp/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
+++ b/csharp/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
@@ -299,6 +299,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       file_.WriteTo(output, _repeated_file_codec);
     }
@@ -545,6 +549,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -889,6 +897,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -1094,6 +1106,10 @@ namespace Google.Protobuf.DescriptorProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Start != 0) {
             output.WriteRawTag(8);
@@ -1236,6 +1252,10 @@ namespace Google.Protobuf.DescriptorProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (Start != 0) {
             output.WriteRawTag(8);
@@ -1475,6 +1495,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -1741,6 +1765,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -1882,6 +1910,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -2051,6 +2083,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -2226,6 +2262,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -2434,6 +2474,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Name.Length != 0) {
         output.WriteRawTag(10);
@@ -2806,6 +2850,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (JavaPackage.Length != 0) {
         output.WriteRawTag(10);
@@ -3173,6 +3221,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (MessageSetWireFormat != false) {
         output.WriteRawTag(8);
@@ -3414,6 +3466,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Ctype != global::Google.Protobuf.DescriptorProtos.FieldOptions.Types.CType.STRING) {
         output.WriteRawTag(8);
@@ -3649,6 +3705,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (AllowAlias != false) {
         output.WriteRawTag(16);
@@ -3797,6 +3857,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Deprecated != false) {
         output.WriteRawTag(8);
@@ -3931,6 +3995,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Deprecated != false) {
         output.WriteRawTag(136, 2);
@@ -4065,6 +4133,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       if (Deprecated != false) {
         output.WriteRawTag(136, 2);
@@ -4264,6 +4336,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       name_.WriteTo(output, _repeated_name_codec);
       if (IdentifierValue.Length != 0) {
@@ -4470,6 +4546,10 @@ namespace Google.Protobuf.DescriptorProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           if (NamePart_.Length != 0) {
             output.WriteRawTag(10);
@@ -4603,6 +4683,10 @@ namespace Google.Protobuf.DescriptorProtos {
       return hash;
     }
 
+    public override string ToString() {
+      return pb::JsonFormatter.Default.Format(this);
+    }
+
     public void WriteTo(pb::CodedOutputStream output) {
       location_.WriteTo(output, _repeated_location_codec);
     }
@@ -4761,6 +4845,10 @@ namespace Google.Protobuf.DescriptorProtos {
           return hash;
         }
 
+        public override string ToString() {
+          return pb::JsonFormatter.Default.Format(this);
+        }
+
         public void WriteTo(pb::CodedOutputStream output) {
           path_.WriteTo(output, _repeated_path_codec);
           span_.WriteTo(output, _repeated_span_codec);
diff --git a/src/google/protobuf/compiler/csharp/csharp_field_base.h b/src/google/protobuf/compiler/csharp/csharp_field_base.h
index 349d835bac..bffa206239 100644
--- a/src/google/protobuf/compiler/csharp/csharp_field_base.h
+++ b/src/google/protobuf/compiler/csharp/csharp_field_base.h
@@ -58,6 +58,7 @@ class FieldGeneratorBase : public SourceGeneratorBase {
 
   virtual void WriteHash(io::Printer* printer) = 0;
   virtual void WriteEquals(io::Printer* printer) = 0;
+  // Currently unused, as we use reflection to generate JSON
   virtual void WriteToString(io::Printer* printer) = 0;
 
  protected:
diff --git a/src/google/protobuf/compiler/csharp/csharp_map_field.cc b/src/google/protobuf/compiler/csharp/csharp_map_field.cc
index cb7ce5f006..32c05232c4 100644
--- a/src/google/protobuf/compiler/csharp/csharp_map_field.cc
+++ b/src/google/protobuf/compiler/csharp/csharp_map_field.cc
@@ -117,12 +117,9 @@ void MapFieldGenerator::WriteEquals(io::Printer* printer) {
     variables_,
     "if (!$property_name$.Equals(other.$property_name$)) return false;\n");
 }
+
 void MapFieldGenerator::WriteToString(io::Printer* printer) {
-    /*
-  variables_["field_name"] = GetFieldName(descriptor_);
-  printer->Print(
-    variables_,
-    "PrintField(\"$field_name$\", has$property_name$, $name$_, writer);\n");*/
+    // TODO: If we ever actually use ToString, we'll need to impleme this...
 }
 
 void MapFieldGenerator::GenerateCloningCode(io::Printer* printer) {
diff --git a/src/google/protobuf/compiler/csharp/csharp_message.cc b/src/google/protobuf/compiler/csharp/csharp_message.cc
index 13544b2681..ac13595178 100644
--- a/src/google/protobuf/compiler/csharp/csharp_message.cc
+++ b/src/google/protobuf/compiler/csharp/csharp_message.cc
@@ -429,7 +429,10 @@ void MessageGenerator::GenerateFrameworkMethods(io::Printer* printer) {
     printer->Outdent();
     printer->Print("}\n\n");
 
-    // TODO(jonskeet): ToString.
+    printer->Print(
+        "public override string ToString() {\n"
+        "  return pb::JsonFormatter.Default.Format(this);\n"
+        "}\n\n");
 }
 
 void MessageGenerator::GenerateMessageSerializationMethods(io::Printer* printer) {