diff --git a/libguac/src/protocol.c b/libguac/src/protocol.c
index 4b7bcbd9..9644aa4f 100644
--- a/libguac/src/protocol.c
+++ b/libguac/src/protocol.c
@@ -501,7 +501,7 @@ int guac_protocol_send_arc(guac_socket* socket, const guac_layer* layer,
         || guac_socket_write_string(socket, ",")
         || __guac_socket_write_length_double(socket, endAngle)
         || guac_socket_write_string(socket, ",")
-        || guac_socket_write_string(socket, negative ? "1" : "0")
+        || guac_socket_write_string(socket, negative ? "1.1" : "1.0")
         || guac_socket_write_string(socket, ";");
 
 }