diff --git a/extensions/b2g/viewer.css b/extensions/b2g/viewer.css
index ab1198d89..b1d3d7c08 100644
--- a/extensions/b2g/viewer.css
+++ b/extensions/b2g/viewer.css
@@ -90,6 +90,7 @@ footer {
 }
 
 #pageNumber {
+  -moz-appearance: textfield; /* hides the spinner in moz */
   position: absolute;
   width: 28%;
   height: 100%;