diff --git a/gcc/gcov-io.c b/gcc/gcov-io.c
index 37c1c3e..28ed52f 100644
--- a/gcc/gcov-io.c
+++ b/gcc/gcov-io.c
@@ -92,7 +92,8 @@ gcov_open (const char *name, int mode)
      {
        /* Read-only mode - acquire a read-lock.  */
        s_flock.l_type = F_RDLCK;
-      fd = open (name, O_RDONLY);
+      /* pass mode (ignored) for compatibility */
+      fd = open (name, O_RDONLY, S_IRUSR | S_IWUSR);
      }
    else
      {