diff --git a/web/viewer_compatibility.js b/web/viewer_compatibility.js
index d73c26834..55b9fc33a 100644
--- a/web/viewer_compatibility.js
+++ b/web/viewer_compatibility.js
@@ -17,8 +17,14 @@ let compatibilityParams = Object.create(null);
 if (typeof PDFJSDev === 'undefined' || PDFJSDev.test('GENERIC')) {
   const userAgent =
     (typeof navigator !== 'undefined' && navigator.userAgent) || '';
+  const platform =
+    (typeof navigator !== 'undefined' && navigator.platform) || '';
+  const maxTouchPoints =
+    (typeof navigator !== 'undefined' && navigator.maxTouchPoints) || 1;
+
   const isAndroid = /Android/.test(userAgent);
-  const isIOS = /\b(iPad|iPhone|iPod)(?=;)/.test(userAgent);
+  const isIOS = /\b(iPad|iPhone|iPod)(?=;)/.test(userAgent) ||
+                (platform === 'MacIntel' && maxTouchPoints > 1);
 
   // Limit canvas size to 5 mega-pixels on mobile.
   // Support: Android, iOS