diff --git a/test/Preprocessor/has_include.c b/test/Preprocessor/has_include.c
index 4e71a36..7cc67fa 100644
--- a/test/Preprocessor/has_include.c
+++ b/test/Preprocessor/has_include.c
@@ -170,3 +170,9 @@
 // expected-error@+1 {{expected "FILENAME" or <FILENAME>}} // expected-error@+1 {{expected value in expression}}
 #if __has_include(<stdint.h)
 #endif
+
+#define HAS_INCLUDE(header) __has_include(header)
+#if HAS_INCLUDE(<stdint.h>)
+#else
+  #error "__has_include failed (9)."
+#endif