diff --git a/ChangeLog b/ChangeLog
index e53fc937f..f4b6fe028 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2016-11-06  Werner Lemberg  <wl@gnu.org>
+
+	* src/base/ftobjs.c (FT_Render_Glyph_Internal): Fix tracing.
+
 2016-11-06  Werner Lemberg  <wl@gnu.org>
 
 	[sfnt] Improve FT_LOAD_BITMAP_METRICS_ONLY for `sbix' format.
diff --git a/src/base/ftobjs.c b/src/base/ftobjs.c
index 060d78e0e..c701ebc93 100644
--- a/src/base/ftobjs.c
+++ b/src/base/ftobjs.c
@@ -4217,7 +4217,7 @@
     if ( ft_trace_levels[trace_bitmap] >= 3 )
     {
       /* we convert to a single bitmap format for computing the checksum */
-      if ( !error )
+      if ( !error && slot->bitmap.buffer )
       {
         FT_Bitmap  bitmap;
         FT_Error   err;