diff --git a/Makefile.am b/Makefile.am
index cf96cbb..c4474cb 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -265,6 +265,15 @@ t/issue330/issue330.pb-c.c t/issue330/issue330.pb-c.h: $(top_builddir)/protoc-c/
 	$(AM_V_GEN)@PROTOC@ --plugin=protoc-gen-c=$(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) -I$(top_srcdir) --c_out=$(top_builddir) $(top_srcdir)/t/issue330/issue330.proto
 BUILT_SOURCES += \
 	t/issue330/issue330.pb-c.c t/issue330/issue330.pb-c.h
+
+t_issue330_issue330_SOURCES += \
+	t/issue389/issue389.pb-c.c # Tack onto issue330 since there is no need for a separate binary here
+t/issue389/issue389.pb-c.c t/issue389/issue389.pb-c.h: $(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) $(top_srcdir)/t/issue389/issue389.proto
+	$(AM_V_GEN)@PROTOC@ --plugin=protoc-gen-c=$(top_builddir)/protoc-c/protoc-gen-c$(EXEEXT) -I$(top_srcdir) --c_out=$(top_builddir) $(top_srcdir)/t/issue389/issue389.proto
+BUILT_SOURCES += \
+	t/issue389/issue389.pb-c.c t/issue389/issue389.pb-c.h
+EXTRA_DIST += \
+	t/issue389/issue389.proto
 endif # BUILD_PROTO3
 EXTRA_DIST += \
 	t/issue330/issue330.proto
diff --git a/protoc-c/c_message.cc b/protoc-c/c_message.cc
index d9a6a33..c7bb844 100755
--- a/protoc-c/c_message.cc
+++ b/protoc-c/c_message.cc
@@ -169,7 +169,7 @@ GenerateStructDefinition(io::Printer* printer) {
       }
       printer->Print(vars, "$ucclassname$__$oneofname$_$fieldname$ = $fieldnum$$opt_comma$\n");
     }
-    printer->Print(vars, "  PROTOBUF_C__FORCE_ENUM_TO_BE_INT_SIZE($ucclassname$__$oneofname$)\n");
+    printer->Print(vars, "  PROTOBUF_C__FORCE_ENUM_TO_BE_INT_SIZE($ucclassname$__$oneofname$__CASE)\n");
     printer->Outdent();
     printer->Print(vars, "} $foneofname$Case;\n\n");
   }
diff --git a/t/issue220/issue220.c b/t/issue220/issue220.c
index 530f755..a1b4578 100644
--- a/t/issue220/issue220.c
+++ b/t/issue220/issue220.c
@@ -8,6 +8,6 @@ int main(void)
 {
 	assert(_MESSAGE_TYPE1__FLAG_IS_INT_SIZE == INT_MAX);
 	assert(_MESSAGE_TYPE2__ANOTHER_FLAG_IS_INT_SIZE == INT_MAX);
-	assert(_TOP_LEVEL__SUBMESSAGES_IS_INT_SIZE == INT_MAX);
+	assert(_TOP_LEVEL__SUBMESSAGES__CASE_IS_INT_SIZE == INT_MAX);
 	return EXIT_SUCCESS;
 }
diff --git a/t/issue389/issue389.proto b/t/issue389/issue389.proto
new file mode 100644
index 0000000..d731848
--- /dev/null
+++ b/t/issue389/issue389.proto
@@ -0,0 +1,12 @@
+syntax = "proto3";
+
+message EnumIntTest {
+  enum Label {
+    LABEL_1 = 0;
+    LABEL_2 = 1;
+  }
+  oneof label {
+    Label label_label = 123;
+    uint64 label_uint64 = 124;
+  }
+}