diff --git a/mach/i86/ncg/mach.h b/mach/i86/ncg/mach.h
index f8ab5d17c..23a41e8f1 100644
--- a/mach/i86/ncg/mach.h
+++ b/mach/i86/ncg/mach.h
@@ -16,8 +16,8 @@
 
 #define cst_fmt         "%d"
 #define off_fmt         "%d"
-#define ilb_fmt         "I%x_%x"
-#define dlb_fmt         "_%d"
+#define ilb_fmt         "I%x_%d"
+#define dlb_fmt         "I_%d"
 #define hol_fmt         "hol%d"
 
 #define hol_off         "%ld+hol%d"