diff --git a/content/html/content/src/nsHTMLAppletElement.cpp b/content/html/content/src/nsHTMLAppletElement.cpp
index c2640770fcf6..86eccdfa6b25 100644
--- a/content/html/content/src/nsHTMLAppletElement.cpp
+++ b/content/html/content/src/nsHTMLAppletElement.cpp
@@ -218,6 +218,7 @@ MapAttributesIntoRule(const nsIHTMLMappedAttributes* aAttributes,
   nsGenericHTMLElement::MapImageBorderAttributeInto(aAttributes, aData);
   nsGenericHTMLElement::MapImageMarginAttributeInto(aAttributes, aData);
   nsGenericHTMLElement::MapImagePositionAttributeInto(aAttributes, aData);
+  nsGenericHTMLElement::MapAlignAttributeInto(aAttributes, aData);
   nsGenericHTMLElement::MapCommonAttributesInto(aAttributes, aData);
 }