diff --git a/upb/test_generated_code.cc b/upb/test_generated_code.cc
index b74b148aba..013ed634a6 100644
--- a/upb/test_generated_code.cc
+++ b/upb/test_generated_code.cc
@@ -361,6 +361,68 @@ TEST(GeneratedCode, ScalarsProto2) {
   upb_Arena_Free(arena);
 }
 
+TEST(GeneratedCode, RepeatedClear) {
+  upb_Arena* arena = upb_Arena_New();
+  protobuf_test_messages_proto2_TestAllTypesProto2* msg =
+      protobuf_test_messages_proto2_TestAllTypesProto2_new(arena);
+  size_t len = 0;
+  protobuf_test_messages_proto2_TestAllTypesProto2_repeated_int32(msg, &len);
+  EXPECT_EQ(0, len);
+  protobuf_test_messages_proto2_TestAllTypesProto2_add_repeated_int32(msg, 2,
+                                                                      arena);
+  protobuf_test_messages_proto2_TestAllTypesProto2_add_repeated_int32(msg, 3,
+                                                                      arena);
+  protobuf_test_messages_proto2_TestAllTypesProto2_add_repeated_int32(msg, 4,
+                                                                      arena);
+  protobuf_test_messages_proto2_TestAllTypesProto2_repeated_int32(msg, &len);
+  EXPECT_EQ(3, len);
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_repeated_int32(msg);
+  protobuf_test_messages_proto2_TestAllTypesProto2_repeated_int32(msg, &len);
+  EXPECT_EQ(0, len);
+  upb_Arena_Free(arena);
+}
+
+TEST(GeneratedCode, Clear) {
+  upb_Arena* arena = upb_Arena_New();
+  protobuf_test_messages_proto2_TestAllTypesProto2* msg =
+      protobuf_test_messages_proto2_TestAllTypesProto2_new(arena);
+  // Test clear.
+  protobuf_test_messages_proto2_TestAllTypesProto2_set_optional_int32(msg, 1);
+  EXPECT_TRUE(
+      protobuf_test_messages_proto2_TestAllTypesProto2_has_optional_int32(msg));
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_optional_int32(msg);
+  EXPECT_EQ(
+      0, protobuf_test_messages_proto2_TestAllTypesProto2_optional_int32(msg));
+  EXPECT_FALSE(
+      protobuf_test_messages_proto2_TestAllTypesProto2_has_optional_int32(msg));
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_optional_int64(msg);
+  EXPECT_EQ(
+      0, protobuf_test_messages_proto2_TestAllTypesProto2_optional_int64(msg));
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_optional_uint32(msg);
+  EXPECT_EQ(
+      0, protobuf_test_messages_proto2_TestAllTypesProto2_optional_uint32(msg));
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_optional_uint64(msg);
+  EXPECT_EQ(
+      0, protobuf_test_messages_proto2_TestAllTypesProto2_optional_uint64(msg));
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_optional_float(msg);
+  EXPECT_EQ(
+      0.0f,
+      protobuf_test_messages_proto2_TestAllTypesProto2_optional_float(msg));
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_optional_double(msg);
+  EXPECT_EQ(
+      0.0,
+      protobuf_test_messages_proto2_TestAllTypesProto2_optional_double(msg));
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_optional_bool(msg);
+  EXPECT_EQ(
+      false,
+      protobuf_test_messages_proto2_TestAllTypesProto2_optional_bool(msg));
+  protobuf_test_messages_proto2_TestAllTypesProto2_clear_optional_string(msg);
+  EXPECT_EQ(
+      0, protobuf_test_messages_proto2_TestAllTypesProto2_optional_string(msg)
+             .size);
+  upb_Arena_Free(arena);
+}
+
 TEST(GeneratedCode, Bytes) {
   upb_Arena* arena = upb_Arena_New();
   protobuf_test_messages_proto2_TestAllTypesProto2* msg =
@@ -425,86 +487,6 @@ TEST(GeneratedCode, Bytes) {
   upb_Arena_Free(arena);
 }
 
-TEST(GeneratedCode, Extension) {
-  upb_Arena* arena = upb_Arena_New();
-  protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrect* msg =
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrect_new(
-          arena);
-  protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrect* msg2;
-  upb_StringView serialized;
-
-  EXPECT_EQ(
-      false,
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_has_message_set_extension(
-          msg));
-
-  protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2* ext =
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_new(
-          arena);
-  EXPECT_EQ(
-      0,
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_i(
-          ext));
-  protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_set_i(
-      ext, 5);
-  EXPECT_EQ(
-      5,
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_i(
-          ext));
-  // Test setter/hazzer.
-  protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_set_message_set_extension(
-      msg, ext, arena);
-  EXPECT_EQ(
-      true,
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_has_message_set_extension(
-          msg));
-  // Test serialize.
-  serialized.data =
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrect_serialize(
-          msg, arena, &serialized.size);
-  msg2 =
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrect_parse(
-          serialized.data, serialized.size, arena);
-  const protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2*
-      ext2 =
-          protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_message_set_extension(
-              msg);
-  EXPECT_EQ(
-      5,
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_i(
-          ext2));
-
-  // Test Clear.
-  protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_clear_message_set_extension(
-      msg);
-  EXPECT_EQ(
-      false,
-      protobuf_test_messages_proto2_TestAllTypesProto2_MessageSetCorrectExtension2_has_message_set_extension(
-          msg));
-  upb_Arena_Free(arena);
-}
-
-TEST(GeneratedCode, RepeatedClear) {
-  upb_Arena* arena = upb_Arena_New();
-  protobuf_test_messages_proto2_TestAllTypesProto2* msg =
-      protobuf_test_messages_proto2_TestAllTypesProto2_new(arena);
-  size_t len = 0;
-  protobuf_test_messages_proto2_TestAllTypesProto2_repeated_int32(msg, &len);
-  EXPECT_EQ(0, len);
-  protobuf_test_messages_proto2_TestAllTypesProto2_add_repeated_int32(msg, 2,
-                                                                      arena);
-  protobuf_test_messages_proto2_TestAllTypesProto2_add_repeated_int32(msg, 3,
-                                                                      arena);
-  protobuf_test_messages_proto2_TestAllTypesProto2_add_repeated_int32(msg, 4,
-                                                                      arena);
-  protobuf_test_messages_proto2_TestAllTypesProto2_repeated_int32(msg, &len);
-  EXPECT_EQ(3, len);
-  protobuf_test_messages_proto2_TestAllTypesProto2_clear_repeated_int32(msg);
-  protobuf_test_messages_proto2_TestAllTypesProto2_repeated_int32(msg, &len);
-  EXPECT_EQ(0, len);
-  upb_Arena_Free(arena);
-}
-
 TEST(GeneratedCode, UTF8) {
   const char invalid_utf8[] = "\xff";
   const upb_StringView invalid_utf8_view =
diff --git a/upbc/protoc-gen-upb.cc b/upbc/protoc-gen-upb.cc
index 61d4980357..524ebccaae 100644
--- a/upbc/protoc-gen-upb.cc
+++ b/upbc/protoc-gen-upb.cc
@@ -923,13 +923,25 @@ void GenerateClear(const protobuf::FieldDescriptor* field,
         field->number(), oneof_fullname, default_value);
   } else {
     if (field->message_type()) {
-      output(
-          R"cc(
-            UPB_INLINE void $0_clear_$1(const $0* msg) {
-              *UPB_PTR_AT(msg, $2, const upb_Message*) = NULL;
-            }
-          )cc",
-          msg_name, field->name(), layout.GetFieldOffset(field));
+      if (layout.HasHasbit(field)) {
+        output(
+            R"cc(
+              UPB_INLINE void $0_clear_$1(const $0* msg) {
+                *UPB_PTR_AT(msg, $2, const upb_Message*) = NULL;
+                _upb_clearhas(msg, $3);
+              }
+            )cc",
+            msg_name, field->name(), layout.GetFieldOffset(field),
+            layout.GetHasbitIndex(field));
+      } else {
+        output(
+            R"cc(
+              UPB_INLINE void $0_clear_$1(const $0* msg) {
+                *UPB_PTR_AT(msg, $2, const upb_Message*) = NULL;
+              }
+            )cc",
+            msg_name, field->name(), layout.GetFieldOffset(field));
+      }
     } else if (layout.HasHasbit(field)) {
       if (field->cpp_type() == protobuf::FieldDescriptor::CPPTYPE_STRING) {
         output(
@@ -979,13 +991,25 @@ void GenerateClear(const protobuf::FieldDescriptor* field,
 void GenerateRepeatedClear(const protobuf::FieldDescriptor* field,
                            const FileLayout& layout, absl::string_view msg_name,
                            Output& output) {
-  output(
-      R"cc(
-        UPB_INLINE void $0_clear_$1(const $0* msg) {
-          _upb_array_detach(msg, $2);
-        }
-      )cc",
-      msg_name, field->name(), layout.GetFieldOffset(field));
+  if (layout.HasHasbit(field)) {
+    output(
+        R"cc(
+          UPB_INLINE void $0_clear_$1(const $0* msg) {
+            _upb_array_detach(msg, $2);
+            _upb_clearhas(msg, $4);
+          }
+        )cc",
+        msg_name, field->name(), layout.GetFieldOffset(field),
+        layout.GetHasbitIndex(field));
+  } else {
+    output(
+        R"cc(
+          UPB_INLINE void $0_clear_$1(const $0* msg) {
+            _upb_array_detach(msg, $2);
+          }
+        )cc",
+        msg_name, field->name(), layout.GetFieldOffset(field));
+  }
 }
 
 void GenerateMapGetters(const protobuf::FieldDescriptor* field,
@@ -1910,7 +1934,7 @@ int WriteExtensions(const FileLayout& layout, Output& output) {
   return exts.size();
 }
 
-// Writes a .upb.c source file.
+// Writes a .upb.cc source file.
 void WriteSource(const FileLayout& layout, Output& output,
                  bool fasttable_enabled) {
   const protobuf::FileDescriptor* file = layout.descriptor();