diff --git a/winsup/cygwin/gmon.h b/winsup/cygwin/gmon.h
index 38070d3c7..3612aac96 100644
--- a/winsup/cygwin/gmon.h
+++ b/winsup/cygwin/gmon.h
@@ -50,13 +50,8 @@
 #if 0
 #include <profile.h>
 #else
-#ifndef _WIN64
-#define _MCOUNT_CALL __attribute__ ((regparm (2)))
-extern void _mcount(void);
-#else
 #define _MCOUNT_CALL
 extern void mcount(void);
-#endif
 #define _MCOUNT_DECL __attribute__((gnu_inline)) __inline__ \
    void _MCOUNT_CALL _mcount_private
 #define MCOUNT