diff --git a/TrimSPelec.js b/TrimSPelec.js
index 98ac8ed..bf57fa5 100644
--- a/TrimSPelec.js
+++ b/TrimSPelec.js
@@ -2,6 +2,11 @@
 
 // Load required packages
 const Plotly = require('plotly.js-dist');
+// Electron wraps every renderer <script> in its own CommonJS module scope, so
+// the bundled Plotly object must be exported to the global scope explicitly.
+// myplots.js and TrimSPlib.js call Plotly.plot/relayout/purge as a global on
+// the main window and inside the Plot-menu popup windows.
+window.Plotly = Plotly;
 const ipcRenderer = require('electron').ipcRenderer;
 const fs = require('fs');
 const { execSync, execFile } = require('child_process');