diff --git a/Makefile.am b/Makefile.am
index 9f078f6..b59768e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -193,6 +193,9 @@ check_PROGRAMS += \
 TESTS += \
 	t/generated-code3/test-generated-code3
 
+t_generated_code3_test_generated_code3_CPPFLAGS = \
+	-DPROTO3
+
 t_generated_code3_test_generated_code3_LDADD = \
 	protobuf-c/libprotobuf-c.la
 
diff --git a/protobuf-c/protobuf-c.c b/protobuf-c/protobuf-c.c
index 39819b4..c092d34 100644
--- a/protobuf-c/protobuf-c.c
+++ b/protobuf-c/protobuf-c.c
@@ -523,6 +523,20 @@ optional_field_get_packed_size(const ProtobufCFieldDescriptor *field,
 	return required_field_get_packed_size(field, member);
 }
 
+static protobuf_c_boolean
+field_is_zeroish(const ProtobufCFieldDescriptor *field,
+		 const void *member)
+{
+	if (field->type == PROTOBUF_C_TYPE_MESSAGE ||
+	    field->type == PROTOBUF_C_TYPE_STRING)
+	{
+	    const void *ptr = *(const void * const *) member;
+	    if (ptr == NULL)
+		    return TRUE;
+	}
+	return member == NULL;
+}
+
 /**
  * Calculate the serialized size of a single unlabeled message field, including
  * the space needed by the preceding tag. Returns 0 if the field isn't set or
@@ -540,10 +554,8 @@ static size_t
 unlabeled_field_get_packed_size(const ProtobufCFieldDescriptor *field,
 				const void *member)
 {
-	const void *ptr = *(const void * const *) member;
-	if (ptr == NULL) {
+	if (field_is_zeroish(field, member))
 		return 0;
-	}
 	return required_field_get_packed_size(field, member);
 }
 
@@ -1168,10 +1180,8 @@ static size_t
 unlabeled_field_pack(const ProtobufCFieldDescriptor *field,
 		     const void *member, uint8_t *out)
 {
-	const void *ptr = *(const void * const *) member;
-	if (ptr == NULL) {
+	if (field_is_zeroish(field, member))
 		return 0;
-	}
 	return required_field_pack(field, member, out);
 }
 
@@ -1673,10 +1683,8 @@ static size_t
 unlabeled_field_pack_to_buffer(const ProtobufCFieldDescriptor *field,
 			       const void *member, ProtobufCBuffer *buffer)
 {
-	const void *ptr = *(const void *const *) member;
-	if (ptr == NULL) {
+	if (field_is_zeroish(field, member))
 		return 0;
-	}
 	return required_field_pack_to_buffer(field, member, buffer);
 }
 
diff --git a/t/generated-code/test-generated-code.c b/t/generated-code/test-generated-code.c
index 1d62094..7443a09 100644
--- a/t/generated-code/test-generated-code.c
+++ b/t/generated-code/test-generated-code.c
@@ -1,10 +1,17 @@
+#ifdef PROTO3
+#include "t/test-proto3.pb-c.h"
+#else
 #include "t/test.pb-c.h"
+#endif
 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
 
-int main()
+int main(void)
 {
+  Foo__Person__PhoneNumber__Comment comment = FOO__PERSON__PHONE_NUMBER__COMMENT__INIT;
+  Foo__Person__PhoneNumber phone = FOO__PERSON__PHONE_NUMBER__INIT;
+  Foo__Person__PhoneNumber *phone_numbers[1];
   Foo__Person person = FOO__PERSON__INIT;
   Foo__Person *person2;
   unsigned char simple_pad[8];
@@ -12,21 +19,43 @@ int main()
   unsigned char *packed;
   ProtobufCBufferSimple bs = PROTOBUF_C_BUFFER_SIMPLE_INIT (simple_pad);
 
+  comment.comment = "protobuf-c guy";
+
+  phone.number = "1234";
+#ifndef PROTO3
+  phone.has_type = 1;
+#endif
+  phone.type = FOO__PERSON__PHONE_TYPE__WORK;
+  phone.comment = &comment;
+
+  phone_numbers[0] = &phone;
+
   person.name = "dave b";
   person.id = 42;
+  person.n_phone = 1;
+  person.phone = phone_numbers;
+
   size = foo__person__get_packed_size (&person);
   packed = malloc (size);
   assert (packed);
+
   size2 = foo__person__pack (&person, packed);
+
   assert (size == size2);
   foo__person__pack_to_buffer (&person, &bs.base);
   assert (bs.len == size);
   assert (memcmp (bs.data, packed, size) == 0);
+
   PROTOBUF_C_BUFFER_SIMPLE_CLEAR (&bs);
+
   person2 = foo__person__unpack (NULL, size, packed);
   assert (person2 != NULL);
   assert (person2->id == 42);
   assert (strcmp (person2->name, "dave b") == 0);
+  assert (person2->n_phone == 1);
+  assert (strcmp (person2->phone[0]->number, "1234") == 0);
+  assert (person2->phone[0]->type == FOO__PERSON__PHONE_TYPE__WORK);
+  assert (strcmp (person2->phone[0]->comment->comment, "protobuf-c guy") == 0);
 
   foo__person__free_unpacked (person2, NULL);
   free (packed);
diff --git a/t/test-proto3.proto b/t/test-proto3.proto
index 41da791..83fdf2a 100644
--- a/t/test-proto3.proto
+++ b/t/test-proto3.proto
@@ -14,8 +14,13 @@ message Person {
   }
 
   message PhoneNumber {
+    message Comment {
+      string comment = 1;
+    }
+
     string number = 1;
     PhoneType type = 2;
+    Comment comment = 3;
   }
 
   repeated PhoneNumber phone = 4;
diff --git a/t/test.proto b/t/test.proto
index bc94f13..bda724e 100644
--- a/t/test.proto
+++ b/t/test.proto
@@ -12,8 +12,13 @@ message Person {
   }
 
   message PhoneNumber {
+    message Comment {
+      required string comment = 1;
+    }
+
     required string number = 1;
     optional PhoneType type = 2 [default = HOME];
+    optional Comment comment = 3;
   }
 
   repeated PhoneNumber phone = 4;