diff --git a/java/pom.xml b/java/pom.xml
index d263bec..1f110d9 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -211,6 +211,12 @@
                   <arg value="--proto_path=src/test/java" />
                   <arg value="../src/google/protobuf/unittest_reference_types_nano.proto" />
                 </exec>
+                <exec executable="../src/protoc">
+                  <arg value="--javanano_out=optional_field_style=reftypes_compat_mode,generate_equals=true,java_outer_classname=google/protobuf/unittest_reference_types_nano.proto|NanoReferenceTypesCompat:target/generated-test-sources" />
+                  <arg value="--proto_path=../src" />
+                  <arg value="--proto_path=src/test/java" />
+                  <arg value="../src/google/protobuf/unittest_reference_types_nano.proto" />
+                </exec>
               </tasks>
               <testSourceRoot>target/generated-test-sources</testSourceRoot>
               <!--testSourceRoot>target/generated-test-sources/opt-space</testSourceRoot-->
diff --git a/java/src/test/java/com/google/protobuf/NanoTest.java b/java/src/test/java/com/google/protobuf/NanoTest.java
index aa555c8..81e57c0 100644
--- a/java/src/test/java/com/google/protobuf/NanoTest.java
+++ b/java/src/test/java/com/google/protobuf/NanoTest.java
@@ -49,6 +49,7 @@
 import com.google.protobuf.nano.NanoOuterClass;
 import com.google.protobuf.nano.NanoOuterClass.TestAllTypesNano;
 import com.google.protobuf.nano.NanoReferenceTypes;
+import com.google.protobuf.nano.NanoReferenceTypesCompat;
 import com.google.protobuf.nano.NanoRepeatedPackables;
 import com.google.protobuf.nano.PackedExtensions;
 import com.google.protobuf.nano.RepeatedExtensions;
@@ -3789,6 +3790,11 @@
     assertTrue(Arrays.equals(new boolean[] {false, true, false, true}, nonPacked.bools));
   }
 
+  public void testRepeatedFieldInitializedInReftypesCompatMode() {
+    NanoReferenceTypesCompat.TestAllTypesNano proto = new NanoReferenceTypesCompat.TestAllTypesNano();
+    assertNotNull(proto.repeatedString);
+  }
+
   private void assertRepeatedPackablesEqual(
       NanoRepeatedPackables.NonPacked nonPacked, NanoRepeatedPackables.Packed packed) {
     // Not using MessageNano.equals() -- that belongs to a separate test.
diff --git a/src/google/protobuf/compiler/javanano/javanano_message.cc b/src/google/protobuf/compiler/javanano/javanano_message.cc
index 7c52ca3..4df3ae8 100644
--- a/src/google/protobuf/compiler/javanano/javanano_message.cc
+++ b/src/google/protobuf/compiler/javanano/javanano_message.cc
@@ -251,14 +251,18 @@
     }
     printer->Print("}\n");
   } else {
+    printer->Print(
+      "\n"
+      "public $classname$() {\n",
+      "classname", descriptor_->name());
     if (params_.generate_clear()) {
-      printer->Print(
-        "\n"
-        "public $classname$() {\n"
-        "  clear();\n"
-        "}\n",
-        "classname", descriptor_->name());
+      printer->Print("  clear();\n");
+    } else {
+      printer->Indent();
+      GenerateFieldInitializers(printer);
+      printer->Outdent();
     }
+    printer->Print("}\n");
   }
 
   // Other methods in this class
@@ -453,6 +457,15 @@
     "classname", descriptor_->name());
   printer->Indent();
 
+  GenerateFieldInitializers(printer);
+
+  printer->Outdent();
+  printer->Print(
+    "  return this;\n"
+    "}\n");
+}
+
+void MessageGenerator::GenerateFieldInitializers(io::Printer* printer) {
   // Clear bit fields.
   int totalInts = (field_generators_.total_bits() + 31) / 32;
   for (int i = 0; i < totalInts; i++) {
@@ -470,12 +483,7 @@
   if (params_.store_unknown_fields()) {
     printer->Print("unknownFieldData = null;\n");
   }
-
-  printer->Outdent();
-  printer->Print(
-    "  cachedSize = -1;\n"
-    "  return this;\n"
-    "}\n");
+  printer->Print("cachedSize = -1;\n");
 }
 
 void MessageGenerator::GenerateEquals(io::Printer* printer) {
diff --git a/src/google/protobuf/compiler/javanano/javanano_message.h b/src/google/protobuf/compiler/javanano/javanano_message.h
index f87f84f..f53c1f7 100644
--- a/src/google/protobuf/compiler/javanano/javanano_message.h
+++ b/src/google/protobuf/compiler/javanano/javanano_message.h
@@ -77,6 +77,7 @@
                                  const FieldDescriptor* field);
 
   void GenerateClear(io::Printer* printer);
+  void GenerateFieldInitializers(io::Printer* printer);
   void GenerateEquals(io::Printer* printer);
   void GenerateHashCode(io::Printer* printer);