diff --git a/mach/proto/ncg/assert.h b/mach/proto/ncg/assert.h
index 8b0ba078f..ce0d6d509 100644
--- a/mach/proto/ncg/assert.h
+++ b/mach/proto/ncg/assert.h
@@ -8,7 +8,7 @@
 #define MACH_PROTO_NCG_ASSERT_H
 
 #ifndef NDEBUG
-#define assert(x) if(!(x)) badassertion("x",__FILE__,__LINE__)
+#define assert(x) if(!(x)) badassertion( #x ,__FILE__,__LINE__)
 #else
 #define assert(x)	/* nothing */
 #endif