diff --git a/godoc/static/godocs.js b/godoc/static/godocs.js
index 7fa805f..47d1de9 100644
--- a/godoc/static/godocs.js
+++ b/godoc/static/godocs.js
@@ -254,7 +254,7 @@
   }
 
   var filename = s.substr(prefix.length);
-  var filenameRE = /^go1\.\d+(\.\d+)?([a-z0-9]+)?\.([a-z0-9]+)-([a-z0-9]+)(-osx10\.[68])?\.([a-z.]+)$/;
+  var filenameRE = /^go1\.\d+(\.\d+)?([a-z0-9]+)?\.([a-z0-9]+)(-[a-z0-9]+)?(-osx10\.[68])?\.([a-z.]+)$/;
   $('.downloadFilename').text(filename);
   $('.hideFromDownload').hide();
   var m = filenameRE.exec(filename);
diff --git a/godoc/static/static.go b/godoc/static/static.go
index f251709..3009e24 100644
--- a/godoc/static/static.go
+++ b/godoc/static/static.go
@@ -819,7 +819,7 @@
   }
 
   var filename = s.substr(prefix.length);
-  var filenameRE = /^go1\.\d+(\.\d+)?([a-z0-9]+)?\.([a-z0-9]+)-([a-z0-9]+)(-osx10\.[68])?\.([a-z.]+)$/;
+  var filenameRE = /^go1\.\d+(\.\d+)?([a-z0-9]+)?\.([a-z0-9]+)(-[a-z0-9]+)?(-osx10\.[68])?\.([a-z.]+)$/;
   $('.downloadFilename').text(filename);
   $('.hideFromDownload').hide();
   var m = filenameRE.exec(filename);