diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index c0f2184..23333eb 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -74,8 +74,8 @@ extern char arm_arch_name[];
 	builtin_define_with_int_value (				\
 	  "__ARM_SIZEOF_MINIMAL_ENUM",				\
 	  flag_short_enums ? 1 : 4);				\
-	builtin_define_with_int_value (				\
-	  "__ARM_SIZEOF_WCHAR_T", WCHAR_TYPE_SIZE);		\
+	builtin_define_type_sizeof ("__ARM_SIZEOF_WCHAR_T",	\
+				    wchar_type_node);		\
 	if (TARGET_ARM_ARCH_PROFILE)				\
 	  builtin_define_with_int_value (			\
 	    "__ARM_ARCH_PROFILE", TARGET_ARM_ARCH_PROFILE);	\