diff --git a/Source/Additions/GSObjCRuntime.m b/Source/Additions/GSObjCRuntime.m
index 5ae8284b0..fc3f63c7d 100644
--- a/Source/Additions/GSObjCRuntime.m
+++ b/Source/Additions/GSObjCRuntime.m
@@ -1091,6 +1091,7 @@ GSObjCGetVal(NSObject *self, const char *key, SEL sel,
 	    break;
 
 #if __GNUC__ != 2
+#ifdef  _C_BOOL
           case _C_BOOL:
             {
               _Bool     v;
@@ -1109,6 +1110,7 @@ GSObjCGetVal(NSObject *self, const char *key, SEL sel,
               val = [NSNumber numberWithBool: (BOOL)v];
             }
             break;
+#endif
 #endif
 
 	  case _C_SHT:
@@ -1556,6 +1558,7 @@ GSObjCSetVal(NSObject *self, const char *key, id val, SEL sel,
 	    break;
 
 #if __GNUC__ != 2
+#ifdef  _C_BOOL
           case _C_BOOL:
             {
               _Bool     v = (_Bool)[val boolValue];
@@ -1575,6 +1578,7 @@ GSObjCSetVal(NSObject *self, const char *key, id val, SEL sel,
                 }
             }
             break;
+#endif
 #endif
 
 	  case _C_SHT: