diff --git a/vhook/imlib2.c b/vhook/imlib2.c
index 64b1bae6871e180d1f6cb2e2e2a1b3d80992ded7..6c6707b78b728aaa779de6604f770c429e649e80 100644
--- a/vhook/imlib2.c
+++ b/vhook/imlib2.c
@@ -249,7 +249,7 @@ void Process(void *ctx, AVPicture *picture, enum PixelFormat pix_fmt, int width,
             }
         }
 
-        strftime(buff, sizeof(buff), tbp, localtime(&now));
+        strftime(buff, sizeof(buff), tbp ? tbp : "[No data]", localtime(&now));
 
         x = ci->x;
         y = ci->y;