diff --git a/src/litegraph.js b/src/litegraph.js
index 8c71971e1..cf6ba04d1 100755
--- a/src/litegraph.js
+++ b/src/litegraph.js
@@ -5697,10 +5697,10 @@ LGraphNode.prototype.executeAction = function(action)
      * @method enableWebGL
      **/
     LGraphCanvas.prototype.enableWebGL = function() {
-        if (typeof GL === undefined) {
+        if (typeof GL === "undefined") {
             throw "litegl.js must be included to use a WebGL canvas";
         }
-        if (typeof enableWebGLCanvas === undefined) {
+        if (typeof enableWebGLCanvas === "undefined") {
             throw "webglCanvas.js must be included to use this feature";
         }
 
@@ -11692,7 +11692,7 @@ LGraphNode.prototype.executeAction = function(action)
                             default:
                                 iS = 0; // try with first if no name set
                         }
-                        if (typeof options.node_from.outputs[iS] !== undefined){
+                        if (typeof options.node_from.outputs[iS] !== "undefined"){
                             if (iS!==false && iS>-1){
                                 options.node_from.connectByType( iS, node, options.node_from.outputs[iS].type );
                             }
@@ -11720,7 +11720,7 @@ LGraphNode.prototype.executeAction = function(action)
                             default:
                                 iS = 0; // try with first if no name set
                         }
-                        if (typeof options.node_to.inputs[iS] !== undefined){
+                        if (typeof options.node_to.inputs[iS] !== "undefined"){
                             if (iS!==false && iS>-1){
                                 // try connection
                                 options.node_to.connectByTypeOutput(iS,node,options.node_to.inputs[iS].type);