diff --git a/APPL/Shared/Shared.inc b/APPL/Shared/Shared.inc
index a9a22c7ac7..a19ee76865 100644
--- a/APPL/Shared/Shared.inc
+++ b/APPL/Shared/Shared.inc
@@ -1277,7 +1277,7 @@ var cache = {
         if (b)
         {
             var eTag = user.lang() + "_" + S("cache_changecounter") + "_" + Session("ASPFIXATION"); // Hoogstens zo lang je ingelogd bent
-            Response.AddHeader("ETag", eTag);
+            Response.AddHeader("ETag", '"' + eTag + '"');
             Response.AddHeader("Last-Modified", new Date().toGMTString());
             Response.CacheControl = "private";
             if (Request.ServerVariables("HTTP_IF_NONE_MATCH") == eTag)