diff --git a/shell/browser/browser_mac.mm b/shell/browser/browser_mac.mm
index 1853c77714244..9c42648b998e9 100644
--- a/shell/browser/browser_mac.mm
+++ b/shell/browser/browser_mac.mm
@@ -444,6 +444,13 @@
     image = native_image->image();
   }
 
+  // This is needed when this fn is called before the browser
+  // process is ready, since supported scales are normally set
+  // by ui::ResourceBundle::InitSharedInstance
+  // during browser process startup.
+  if (!is_ready())
+    gfx::ImageSkia::SetSupportedScales({1.0f});
+
   [[AtomApplication sharedApplication]
       setApplicationIconImage:image.AsNSImage()];
 }