diff --git a/packages/node_modules/@node-red/editor-client/src/js/red.js b/packages/node_modules/@node-red/editor-client/src/js/red.js
index eff0324df..011b5b8d7 100644
--- a/packages/node_modules/@node-red/editor-client/src/js/red.js
+++ b/packages/node_modules/@node-red/editor-client/src/js/red.js
@@ -46,6 +46,14 @@ var RED = (function() {
                     newScript.src = RED.settings.apiRootUrl+srcUrl;
                     hasDeferred = true;
                 } else {
+                    if (/\/ace.js$/.test(srcUrl) || /\/ext-language_tools.js$/.test(srcUrl)) {
+                        // Block any attempts to load ace.js from a CDN - this will
+                        // break the version of ace included in the editor.
+                        // At the time of commit, the contrib-python nodes did this.
+                        // This is a crude fix until the python nodes are fixed.
+                        console.warn("Blocked attempt to load",srcUrl,"by",moduleId)
+                        $(el).remove();
+                    }
                     scriptCount--;
                 }
             })