diff --git a/exec_cmd.c b/exec_cmd.c
index e85f0fd8d8..680b257cd5 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -43,12 +43,10 @@ const char *git_extract_argv0_path(const char *argv0)
 
 	if (!argv0 || !*argv0)
 		return NULL;
-	slash = argv0 + strlen(argv0);
 
-	while (argv0 <= slash && !is_dir_sep(*slash))
-		slash--;
+	slash = find_last_dir_sep(argv0);
 
-	if (slash >= argv0) {
+	if (slash) {
 		argv0_path = xstrndup(argv0, slash - argv0);
 		return slash + 1;
 	}