diff --git a/jetty-http/src/main/java/org/eclipse/jetty/http/CompressedContentFormat.java b/jetty-http/src/main/java/org/eclipse/jetty/http/CompressedContentFormat.java
index 65cdd9b8089..4420e2056e0 100644
--- a/jetty-http/src/main/java/org/eclipse/jetty/http/CompressedContentFormat.java
+++ b/jetty-http/src/main/java/org/eclipse/jetty/http/CompressedContentFormat.java
@@ -61,8 +61,8 @@ public class CompressedContentFormat
             return true;
 
         int dashdash = tag.indexOf("--");
-        if (dashdash>0)
-            return etag.regionMatches(0,tag,0,dashdash-2);
+        if (dashdash>0 && dashdash==etag.length()-1)
+            return etag.regionMatches(0,tag,0,dashdash);
         return false;
     }
 }
diff --git a/jetty-servlet/src/test/java/org/eclipse/jetty/servlet/DefaultServletTest.java b/jetty-servlet/src/test/java/org/eclipse/jetty/servlet/DefaultServletTest.java
index 9aa5bbf123d..65cd960402d 100644
--- a/jetty-servlet/src/test/java/org/eclipse/jetty/servlet/DefaultServletTest.java
+++ b/jetty-servlet/src/test/java/org/eclipse/jetty/servlet/DefaultServletTest.java
@@ -895,6 +895,10 @@ public class DefaultServletTest
         assertResponseNotContains("Content-Encoding: gzip",response);
         assertResponseNotContains("ETag: "+etag_gzip,response);
         assertResponseContains("ETag: ",response);   
+
+        String bad_etag_gzip = etag.substring(0,etag.length()-2)+"X--gzip\"";
+        response = connector.getResponse("GET /context/data0.txt HTTP/1.0\r\nHost:localhost:8080\r\nAccept-Encoding:gzip\r\nIf-None-Match: "+bad_etag_gzip+"\r\n\r\n");
+        assertResponseNotContains("304 Not Modified", response);
         
         response = connector.getResponse("GET /context/data0.txt HTTP/1.0\r\nHost:localhost:8080\r\nAccept-Encoding:gzip\r\nIf-None-Match: "+etag_gzip+"\r\n\r\n");
         assertResponseContains("304 Not Modified", response);