diff --git a/accessible/src/mac/mozActionElements.mm b/accessible/src/mac/mozActionElements.mm
index f22cc992f9f0..f673d8c82107 100644
--- a/accessible/src/mac/mozActionElements.mm
+++ b/accessible/src/mac/mozActionElements.mm
@@ -338,6 +338,19 @@ enum CheckboxValue {
 
 @implementation mozPaneAccessible
 
+- (NSUInteger)accessibilityArrayAttributeCount:(NSString*)attribute
+{
+  if (!mGeckoAccessible)
+    return 0;
+
+  // By default this calls -[[mozAccessible children] count].
+  // Since we don't cache mChildren. This is faster.
+  if ([attribute isEqualToString:NSAccessibilityChildrenAttribute])
+    return mGeckoAccessible->ChildCount() ? 1 : 0;
+
+  return [super accessibilityArrayAttributeCount:attribute];
+}
+
 - (NSArray*)children
 {
   if (!mGeckoAccessible)