diff --git a/src/xdisp.c b/src/xdisp.c
index a99a7eb3f32..83792108f42 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -4934,6 +4934,7 @@ static int
 get_overlay_strings_1 (it, charpos, compute_stop_p)
      struct it *it;
      int charpos;
+     int compute_stop_p;
 {
   /* Get the first OVERLAY_STRING_CHUNK_SIZE overlay strings to
      process.  This fills IT->overlay_strings with strings, and sets