--- a/devtools/client/debugger/debugger-view.js
+++ b/devtools/client/debugger/debugger-view.js
@@ -447,17 +447,17 @@ var DebuggerView = {
    */
   _setEditorMode: function (aUrl, aContentType = "", aTextContent = "") {
     // Use JS mode for files with .js and .jsm extensions.
     if (SourceUtils.isJavaScript(aUrl, aContentType)) {
       return void this.editor.setMode(Editor.modes.js);
     }
 
     if (aContentType === "text/wasm") {
-      return void this.editor.setMode(Editor.modes.wasm);
+      return void this.editor.setMode(Editor.modes.text);
     }
 
     // Use HTML mode for files in which the first non whitespace character is
     // <, regardless of extension.
     if (aTextContent.match(/^\s*</)) {
       return void this.editor.setMode(Editor.modes.html);
     }