diff --git a/examples/example.c b/examples/example.c
index fc156c0..617e7ad 100644
--- a/examples/example.c
+++ b/examples/example.c
@@ -66,6 +66,7 @@ typedef struct ClientData {
 static void clientgone(rfbClientPtr cl)
 {
   free(cl->clientData);
+  cl->clientData = NULL;
 }
 
 static enum rfbNewClientAction newclient(rfbClientPtr cl)
diff --git a/test/encodingstest.c b/test/encodingstest.c
index c6c8255..715e887 100644
--- a/test/encodingstest.c
+++ b/test/encodingstest.c
@@ -172,6 +172,7 @@ static void* clientLoop(void* data) {
 	}
 	free(((clientData*)client->clientData)->display);
 	free(client->clientData);
+	client->clientData = NULL;
 	if(client->frameBuffer)
 		free(client->frameBuffer);
 	rfbClientCleanup(client);