diff --git a/dom/locales/en-US/chrome/layout/css.properties b/dom/locales/en-US/chrome/layout/css.properties
index a0f85a60e980..ec0c5c9fe77c 100644
--- a/dom/locales/en-US/chrome/layout/css.properties
+++ b/dom/locales/en-US/chrome/layout/css.properties
@@ -124,6 +124,6 @@ PEEndOfDeclEOF=end of declaration
 PEImportantEOF=important
 PEExpectedImportant=Expected 'important' but found '%1$S'.
 PEBadDeclEnd=Expected ';' to terminate declaration but found '%1$S'.
-PEBadDeclOrRuleEnd=Expected ';' or '}' to terminate declaration but found"))
+PEBadDeclOrRuleEnd=Expected ';' or '}' to terminate declaration but found '%1$S'.
 PEInaccessibleProperty=Attempt to use inaccessible property
 PECommentEOF=end of comment