diff --git a/parse.c b/parse.c
index 7a60a4f816..3c47448ca6 100644
--- a/parse.c
+++ b/parse.c
@@ -38,7 +38,7 @@ int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
 			errno = EINVAL;
 			return 0;
 		}
-		if ((val < 0 && -max / factor > val) ||
+		if ((val < 0 && (-max - 1) / factor > val) ||
 		    (val > 0 && max / factor < val)) {
 			errno = ERANGE;
 			return 0;