diff --git a/usr.bin/gprof/gprof.h b/usr.bin/gprof/gprof.h
index afe435745caf..27808d2325da 100644
--- a/usr.bin/gprof/gprof.h
+++ b/usr.bin/gprof/gprof.h
@@ -82,7 +82,7 @@ typedef int	bool;
 long	hz;
 
 #ifdef GPROF4
-typedef	unsigned int UNIT;
+typedef	int32_t UNIT;
 #else
 typedef	u_short UNIT;		/* unit of profiling */
 #endif