diff --git a/ui/vnc-enc-tight.c b/ui/vnc-enc-tight.c
index dbde08d..1d926c9 100644
--- a/ui/vnc-enc-tight.c
+++ b/ui/vnc-enc-tight.c
@@ -1659,4 +1659,7 @@ void vnc_tight_clear(VncState *vs)
 #ifdef CONFIG_VNC_JPEG
     buffer_free(&vs->tight.jpeg);
 #endif
+#ifdef CONFIG_VNC_PNG
+    buffer_free(&vs->tight.png);
+#endif
 }