diff --git a/esbuild.js b/esbuild.js
index 41cfad62f..990278cf4 100644
--- a/esbuild.js
+++ b/esbuild.js
@@ -116,23 +116,19 @@ async function main() {
         logLevel: 'info',
     });
 
+    const contexts = [extensionCtx, agentCtx, interactiveRendererCtx, webviewCtx];
     if (watch) {
-        await Promise.all([
-            extensionCtx.watch(),
-            agentCtx.watch(),
-            interactiveRendererCtx.watch(),
-            webviewCtx.watch()
-        ]);
+        await Promise.all(contexts.map(context => context.watch()));
         console.log('Watching for changes...');
     } else {
-        await extensionCtx.rebuild();
-        await agentCtx.rebuild();
-        await interactiveRendererCtx.rebuild();
-        await webviewCtx.rebuild();
-        await extensionCtx.dispose();
-        await agentCtx.dispose();
-        await interactiveRendererCtx.dispose();
-        await webviewCtx.dispose();
+        try {
+            const results = await Promise.all(contexts.map(context => context.rebuild()));
+            if (results.some(result => result.warnings.length > 0)) {
+                throw new Error('Build failed because esbuild reported warnings.');
+            }
+        } finally {
+            await Promise.all(contexts.map(context => context.dispose()));
+        }
     }
 }
 
diff --git a/src/helpViewer/helpPreviewer.ts b/src/helpViewer/helpPreviewer.ts
index 462f1f990..c8d53cd69 100644
--- a/src/helpViewer/helpPreviewer.ts
+++ b/src/helpViewer/helpPreviewer.ts
@@ -2,7 +2,7 @@ import * as path from 'path';
 import * as fs from 'fs';
 import * as vscode from 'vscode';
 import * as rHelp from './index';
-import * as ejs from 'ejs';
+import ejs from 'ejs';
 import { isDirSafe, isFileSafe, readFileSyncSafe, config, spawnAsync } from '../util';
 import { Topic, TopicType } from './packages';
 
diff --git a/src/plotViewer/httpgdViewer.ts b/src/plotViewer/httpgdViewer.ts
index 2e28d4f32..257ac279d 100644
--- a/src/plotViewer/httpgdViewer.ts
+++ b/src/plotViewer/httpgdViewer.ts
@@ -3,7 +3,7 @@ import { HttpgdClient, HttpgdIdResponse, HttpgdPlotId, HttpgdRendererId } from '
 import { HttpgdPlot, IHttpgdViewer, HttpgdViewerOptions } from './httpgdTypes';
 import * as path from 'path';
 import * as fs from 'fs';
-import * as ejs from 'ejs';
+import ejs from 'ejs';
 
 import { asViewColumn, config, setContext, UriIcon, makeWebviewCommandUriString } from '../util';
 import { extensionContext } from '../extension';