diff --git a/csharp/src/Google.Protobuf.Test/testprotos.pb b/csharp/src/Google.Protobuf.Test/testprotos.pb
index 4cac7ba0cc..bc3979e965 100644
Binary files a/csharp/src/Google.Protobuf.Test/testprotos.pb and b/csharp/src/Google.Protobuf.Test/testprotos.pb differ
diff --git a/csharp/src/Google.Protobuf/Reflection/Descriptor.cs b/csharp/src/Google.Protobuf/Reflection/Descriptor.cs
index 3052f73e07..162f17512e 100644
--- a/csharp/src/Google.Protobuf/Reflection/Descriptor.cs
+++ b/csharp/src/Google.Protobuf/Reflection/Descriptor.cs
@@ -1194,6 +1194,9 @@ namespace Google.Protobuf.Reflection {
         private readonly static int StartDefaultValue = 0;
 
         private int start_;
+        /// <summary>
+        /// Inclusive.
+        /// </summary>
         [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
         public int Start {
           get { if ((_hasBits0 & 1) != 0) { return start_; } else { return StartDefaultValue; } }
@@ -1218,6 +1221,9 @@ namespace Google.Protobuf.Reflection {
         private readonly static int EndDefaultValue = 0;
 
         private int end_;
+        /// <summary>
+        /// Exclusive.
+        /// </summary>
         [global::System.Diagnostics.DebuggerNonUserCodeAttribute]
         public int End {
           get { if ((_hasBits0 & 2) != 0) { return end_; } else { return EndDefaultValue; } }
diff --git a/php/src/Google/Protobuf/Internal/DescriptorProto/ExtensionRange.php b/php/src/Google/Protobuf/Internal/DescriptorProto/ExtensionRange.php
index c06a0a6ea9..a2057fd5d1 100644
--- a/php/src/Google/Protobuf/Internal/DescriptorProto/ExtensionRange.php
+++ b/php/src/Google/Protobuf/Internal/DescriptorProto/ExtensionRange.php
@@ -16,11 +16,15 @@ use Google\Protobuf\Internal\GPBUtil;
 class ExtensionRange extends \Google\Protobuf\Internal\Message
 {
     /**
+     * Inclusive.
+     *
      * Generated from protobuf field <code>optional int32 start = 1;</code>
      */
     private $start = 0;
     private $has_start = false;
     /**
+     * Exclusive.
+     *
      * Generated from protobuf field <code>optional int32 end = 2;</code>
      */
     private $end = 0;
@@ -38,7 +42,9 @@ class ExtensionRange extends \Google\Protobuf\Internal\Message
      *     Optional. Data for populating the Message object.
      *
      *     @type int $start
+     *           Inclusive.
      *     @type int $end
+     *           Exclusive.
      *     @type \Google\Protobuf\Internal\ExtensionRangeOptions $options
      * }
      */
@@ -48,6 +54,8 @@ class ExtensionRange extends \Google\Protobuf\Internal\Message
     }
 
     /**
+     * Inclusive.
+     *
      * Generated from protobuf field <code>optional int32 start = 1;</code>
      * @return int
      */
@@ -57,6 +65,8 @@ class ExtensionRange extends \Google\Protobuf\Internal\Message
     }
 
     /**
+     * Inclusive.
+     *
      * Generated from protobuf field <code>optional int32 start = 1;</code>
      * @param int $var
      * @return $this
@@ -76,6 +86,8 @@ class ExtensionRange extends \Google\Protobuf\Internal\Message
     }
 
     /**
+     * Exclusive.
+     *
      * Generated from protobuf field <code>optional int32 end = 2;</code>
      * @return int
      */
@@ -85,6 +97,8 @@ class ExtensionRange extends \Google\Protobuf\Internal\Message
     }
 
     /**
+     * Exclusive.
+     *
      * Generated from protobuf field <code>optional int32 end = 2;</code>
      * @param int $var
      * @return $this