diff --git a/diff-no-index.c b/diff-no-index.c
index 03daadb25a..1f8999b9ca 100644
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -65,8 +65,7 @@ static int populate_from_stdin(struct diff_filespec *s)
 	size_t size = 0;
 
 	if (strbuf_read(&buf, 0, 0) < 0)
-		return error("error while reading from stdin %s",
-				     strerror(errno));
+		return error_errno("error while reading from stdin");
 
 	s->should_munmap = 0;
 	s->data = strbuf_detach(&buf, &size);