diff --git a/llvm/test/Regression/CFrontend/2004-05-21-IncompleteEnum.c b/llvm/test/Regression/CFrontend/2004-05-21-IncompleteEnum.c
new file mode 100644
index 000000000000..1e57a976c5d0
--- /dev/null
+++ b/llvm/test/Regression/CFrontend/2004-05-21-IncompleteEnum.c
@@ -0,0 +1,3 @@
+void test(enum foo *X) {
+}
+