diff --git a/browser/locales/en-US/chrome/browser/aboutRobots.dtd b/browser/locales/en-US/chrome/browser/aboutRobots.dtd
index eb2a26c9c26..91ea0d4e375 100644
--- a/browser/locales/en-US/chrome/browser/aboutRobots.dtd
+++ b/browser/locales/en-US/chrome/browser/aboutRobots.dtd
@@ -16,7 +16,7 @@
 <!-- Movie: Blade Runner. Batty: "I've seen things you people wouldn't believe..." -->
 <!ENTITY robots.errorLongDesc2 "Robots have seen things you people wouldn't believe.">
 <!-- Book: Hitchiker's Guide To The Galaxy. What the Sirius Cybernetics Corporation calls robots. -->
-<!ENTITY robots.errorLongDesc3 "Robots are Your Plastic Pal Who's Fun To Be With">
+<!ENTITY robots.errorLongDesc3 "Robots are Your Plastic Pal Who's Fun To Be With.">
 <!-- TV: Futurama. Bender's first line is "Bite my shiny metal ass." -->
 <!ENTITY robots.errorLongDesc4 "Robots have shiny metal posteriors which should not be bitten.">
 <!-- TV: Battlestar Galactica (2004 series). From the opening text. -->