diff --git a/client_examples/gtkvncviewer.c b/client_examples/gtkvncviewer.c
index 261b2da..861e4e3 100644
--- a/client_examples/gtkvncviewer.c
+++ b/client_examples/gtkvncviewer.c
@@ -588,7 +588,7 @@ static void GtkDefaultLog (const char *format, ...)
 
 	time (&log_clock);
 	strftime (buf, 255, "%d/%m/%Y %X ", localtime (&log_clock));
-	fprintf (stdout, buf);
+	fprintf (stdout, "%s", buf);
 
 	vfprintf (stdout, format, args);
 	fflush (stdout);
diff --git a/libvncclient/zrle.c b/libvncclient/zrle.c
index 7f488b5..0128146 100644
--- a/libvncclient/zrle.c
+++ b/libvncclient/zrle.c
@@ -198,7 +198,7 @@ HandleZRLE (rfbClient* client, int rx, int ry, int rw, int rh)
 			for(i=0; i<rw; i+=rfbZRLETileWidth) {
 				int subWidth=(i+rfbZRLETileWidth>rw)?rw-i:rfbZRLETileWidth;
 				int subHeight=(j+rfbZRLETileHeight>rh)?rh-j:rfbZRLETileHeight;
-				int result=HandleZRLETile(client,buf,remaining,rx+i,ry+j,subWidth,subHeight);
+				int result=HandleZRLETile(client,(uint8_t *)buf,remaining,rx+i,ry+j,subWidth,subHeight);
 
 				if(result<0) {
 					rfbClientLog("ZRLE decoding failed (%d)\n",result);