diff --git a/browser/app/macbuild/Contents/Info.plist.in b/browser/app/macbuild/Contents/Info.plist.in
index 6212e886db..d6902fffde 100644
--- a/browser/app/macbuild/Contents/Info.plist.in
+++ b/browser/app/macbuild/Contents/Info.plist.in
@@ -205,6 +205,11 @@
 	<true/>
 	<key>LSApplicationCategoryType</key>
 	<string>public.app-category.productivity</string>
+	<key>LSEnvironment</key>
+	<dict>
+		<key>MallocNanoZone</key>
+		<string>0</string>
+	</dict>
 	<key>LSFileQuarantineEnabled</key>
 	<true/>
 	<key>LSMinimumSystemVersion</key>
diff --git a/memory/build/replace_malloc.c b/memory/build/replace_malloc.c
index 88dfde33c4..26dd8c2d6b 100644
--- a/memory/build/replace_malloc.c
+++ b/memory/build/replace_malloc.c
@@ -513,6 +513,12 @@ register_zone(void)
    */
   malloc_zone_t *purgeable_zone = malloc_default_purgeable_zone();
 
+  // There is a problem related to the above with the system nano zone, which
+  // is hard to work around from here, and that is instead worked around by
+  // disabling the nano zone through an environment variable
+  // (MallocNanoZone=0). In Firefox, we do that through
+  // browser/app/macbuild/Contents/Info.plist.in.
+
   /* Register the custom zone.  At this point it won't be the default. */
   malloc_zone_register(&zone);