diff --git a/libf2c/arithchk.c b/libf2c/arithchk.c
index 8e15722..a1a03ac 100644
--- a/libf2c/arithchk.c
+++ b/libf2c/arithchk.c
@@ -110,7 +110,7 @@ icheck(void)
 	return 0;
 	}
 
-char *emptyfmt = "";	/* avoid possible warning message with printf("") */
+const char emptyfmt[] = "";	/* avoid possible warning message with printf("") */
 
  static Akind *
 ccheck(void)