diff --git a/toolkit/themes/gnomestripe/mozapps/extensions/extensions.css b/toolkit/themes/gnomestripe/mozapps/extensions/extensions.css
index 07759823e2c..2b418a8e537 100644
--- a/toolkit/themes/gnomestripe/mozapps/extensions/extensions.css
+++ b/toolkit/themes/gnomestripe/mozapps/extensions/extensions.css
@@ -42,6 +42,10 @@
   -moz-margin-end: 5px;
 }
 
+#checkUpdatesAllButton {
+  list-style-image: none;
+}
+
 #installFileButton, #installUpdatesAllButton {
   -moz-image-region: rect(0px, 84px, 21px, 63px);
 }
diff --git a/toolkit/themes/winstripe/mozapps/extensions/extensions.css b/toolkit/themes/winstripe/mozapps/extensions/extensions.css
index 9fcc69ee8a2..6158277b053 100644
--- a/toolkit/themes/winstripe/mozapps/extensions/extensions.css
+++ b/toolkit/themes/winstripe/mozapps/extensions/extensions.css
@@ -41,6 +41,10 @@
   -moz-margin-end: 5px;
 }
 
+#checkUpdatesAllButton {
+  list-style-image: none;
+}
+
 #installFileButton, #installUpdatesAllButton {
   -moz-image-region: rect(0px, 84px, 21px, 63px);
 }