diff --git a/test/Sema/attr-mode.c b/test/Sema/attr-mode.c
index 0b28532..f8cc4dc 100644
--- a/test/Sema/attr-mode.c
+++ b/test/Sema/attr-mode.c
@@ -58,6 +58,7 @@
 #elif TEST_64BIT_X86
 void test_long_to_i64(long* y) { f_i64_arg(y); }
 void test_long_to_ui64(unsigned long* y) { f_ui64_arg(y); }
+typedef          float f128ibm __attribute__ ((mode (TF)));     // expected-error{{unsupported machine mode 'TF'}}
 #elif TEST_64BIT_PPC64
 typedef          float f128ibm __attribute__ ((mode (TF)));
 typedef _Complex float c128ibm __attribute__ ((mode (TC)));