diff --git a/src/google/protobuf/compiler/javanano/javanano_enum_field.cc b/src/google/protobuf/compiler/javanano/javanano_enum_field.cc
index acb8dc2d5d..420d3c2d2b 100644
--- a/src/google/protobuf/compiler/javanano/javanano_enum_field.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_enum_field.cc
@@ -89,11 +89,11 @@ EnumFieldGenerator::~EnumFieldGenerator() {}
 void EnumFieldGenerator::
 GenerateMembers(io::Printer* printer) const {
   printer->Print(variables_,
-    "public $type$ $name$ = $default$;\n");
+    "public $type$ $name$;\n");
 
   if (params_.generate_has()) {
     printer->Print(variables_,
-      "public boolean has$capitalized_name$ = false;\n");
+      "public boolean has$capitalized_name$;\n");
   }
 }
 
@@ -178,7 +178,7 @@ AccessorEnumFieldGenerator::~AccessorEnumFieldGenerator() {}
 void AccessorEnumFieldGenerator::
 GenerateMembers(io::Printer* printer) const {
   printer->Print(variables_,
-    "private int $name$_ = $default$;\n"
+    "private int $name$_;\n"
     "public int get$capitalized_name$() {\n"
     "  return $name$_;\n"
     "}\n"
@@ -241,7 +241,7 @@ RepeatedEnumFieldGenerator::~RepeatedEnumFieldGenerator() {}
 void RepeatedEnumFieldGenerator::
 GenerateMembers(io::Printer* printer) const {
   printer->Print(variables_,
-    "public $type$[] $name$ = $repeated_default$;\n");
+    "public $type$[] $name$;\n");
   if (descriptor_->options().packed()) {
     printer->Print(variables_,
       "private int $name$MemoizedSerializedSize;\n");
diff --git a/src/google/protobuf/compiler/javanano/javanano_message.cc b/src/google/protobuf/compiler/javanano/javanano_message.cc
index c9ea654ec1..420405d207 100644
--- a/src/google/protobuf/compiler/javanano/javanano_message.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_message.cc
@@ -144,7 +144,9 @@ void MessageGenerator::Generate(io::Printer* printer) {
   printer->Indent();
   printer->Print(
     "public static final $classname$ EMPTY_ARRAY[] = {};\n"
-    "public $classname$() {}\n"
+    "public $classname$() {\n"
+    "  clear();\n"
+    "}\n"
     "\n",
     "classname", descriptor_->name());
 
@@ -244,7 +246,7 @@ GenerateMessageSerializationMethods(io::Printer* printer) {
   printer->Print(
     "}\n"
     "\n"
-    "private int cachedSize = -1;\n"
+    "private int cachedSize;\n"
     "@Override\n"
     "public int getCachedSize() {\n"
     "  if (cachedSize < 0) {\n"
diff --git a/src/google/protobuf/compiler/javanano/javanano_message_field.cc b/src/google/protobuf/compiler/javanano/javanano_message_field.cc
index 02dbdb1742..277eb4e131 100644
--- a/src/google/protobuf/compiler/javanano/javanano_message_field.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_message_field.cc
@@ -84,7 +84,7 @@ MessageFieldGenerator::~MessageFieldGenerator() {}
 void MessageFieldGenerator::
 GenerateMembers(io::Printer* printer) const {
   printer->Print(variables_,
-    "public $type$ $name$ = null;\n");
+    "public $type$ $name$;\n");
 }
 
 void MessageFieldGenerator::
@@ -144,7 +144,7 @@ AccessorMessageFieldGenerator::~AccessorMessageFieldGenerator() {}
 void AccessorMessageFieldGenerator::
 GenerateMembers(io::Printer* printer) const {
   printer->Print(variables_,
-    "private $type$ $name$_ = null;\n"
+    "private $type$ $name$_;\n"
     "public $type$ get$capitalized_name$() {\n"
     "  return $name$_;\n"
     "}\n"
@@ -218,7 +218,7 @@ RepeatedMessageFieldGenerator::~RepeatedMessageFieldGenerator() {}
 void RepeatedMessageFieldGenerator::
 GenerateMembers(io::Printer* printer) const {
   printer->Print(variables_,
-    "public $type$[] $name$ = $type$.EMPTY_ARRAY;\n");
+    "public $type$[] $name$;\n");
 }
 
 void RepeatedMessageFieldGenerator::
@@ -231,7 +231,8 @@ void RepeatedMessageFieldGenerator::
 GenerateMergingCode(io::Printer* printer) const {
   // First, figure out the length of the array, then parse.
   printer->Print(variables_,
-    "int arrayLength = com.google.protobuf.nano.WireFormatNano.getRepeatedFieldArrayLength(input, $tag$);\n"
+    "int arrayLength = com.google.protobuf.nano.WireFormatNano"
+    "    .getRepeatedFieldArrayLength(input, $tag$);\n"
     "int i = this.$name$.length;\n"
     "$type$[] newArray = new $type$[i + arrayLength];\n"
     "System.arraycopy(this.$name$, 0, newArray, 0, i);\n"
diff --git a/src/google/protobuf/compiler/javanano/javanano_primitive_field.cc b/src/google/protobuf/compiler/javanano/javanano_primitive_field.cc
index d71b30b20b..f5e27d6025 100644
--- a/src/google/protobuf/compiler/javanano/javanano_primitive_field.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_primitive_field.cc
@@ -315,7 +315,7 @@ GenerateMembers(io::Printer* printer) const {
   }
 
   printer->Print(variables_,
-    "public $type$ $name$ = $default_copy_if_needed$;\n");
+    "public $type$ $name$;\n");
 
   if (params_.generate_has()) {
     printer->Print(variables_,
@@ -427,7 +427,7 @@ GenerateMembers(io::Printer* printer) const {
       "private static final $type$ $default_constant$ = $default_constant_value$;\n");
   }
   printer->Print(variables_,
-    "private $type$ $name$_ = $default_copy_if_needed$;\n"
+    "private $type$ $name$_;\n"
     "public $type$ get$capitalized_name$() {\n"
     "  return $name$_;\n"
     "}\n"
@@ -495,7 +495,7 @@ RepeatedPrimitiveFieldGenerator::~RepeatedPrimitiveFieldGenerator() {}
 void RepeatedPrimitiveFieldGenerator::
 GenerateMembers(io::Printer* printer) const {
   printer->Print(variables_,
-    "public $type$[] $name$ = $default$;\n");
+    "public $type$[] $name$;\n");
 }
 
 void RepeatedPrimitiveFieldGenerator::
@@ -526,7 +526,8 @@ GenerateMergingCode(io::Printer* printer) const {
       "input.popLimit(limit);\n");
   } else {
     printer->Print(variables_,
-      "int arrayLength = com.google.protobuf.nano.WireFormatNano.getRepeatedFieldArrayLength(input, $tag$);\n"
+      "int arrayLength = com.google.protobuf.nano.WireFormatNano\n"
+      "    .getRepeatedFieldArrayLength(input, $tag$);\n"
       "int i = this.$name$.length;\n");
 
     if (GetJavaType(descriptor_) == JAVATYPE_BYTES) {