diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 246823cd2a5..49dd3b818fe 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2011-11-29  Yufeng Zhang  <yufeng.zhang@arm.com>
+
+	Use complex floating-point constant in CDBL.
+
+	* gcc.dg/compat/compat-common.h (CDBL): Replace 1i with 1.0i.
+
 2011-11-29  Tobias Burnus  <burnus@net-b.de>
 
 	PR fortran/51306
diff --git a/gcc/testsuite/gcc.dg/compat/compat-common.h b/gcc/testsuite/gcc.dg/compat/compat-common.h
index 8a92ea3e606..4b3fb9c14ca 100644
--- a/gcc/testsuite/gcc.dg/compat/compat-common.h
+++ b/gcc/testsuite/gcc.dg/compat/compat-common.h
@@ -33,7 +33,7 @@
 #ifndef SKIP_COMPLEX
 #ifdef __GNUC__
 #define CINT(x, y) (x + y * __extension__ 1i)
-#define CDBL(x, y) (x + y * __extension__ 1i)
+#define CDBL(x, y) (x + y * __extension__ 1.0i)
 #else
 #ifdef __SUNPRO_C
 /* ??? Complex support without <complex.h>.  */