diff --git a/src/main/java/org/mitre/dsmiley/httpproxy/ProxyServlet.java b/src/main/java/org/mitre/dsmiley/httpproxy/ProxyServlet.java
index 41b2983..6a30945 100755
--- a/src/main/java/org/mitre/dsmiley/httpproxy/ProxyServlet.java
+++ b/src/main/java/org/mitre/dsmiley/httpproxy/ProxyServlet.java
@@ -562,6 +562,8 @@ protected void copyResponseHeader(HttpServletRequest servletRequest,
     String headerName = header.getName();
     if (hopByHopHeaders.containsHeader(headerName))
       return;
+    if (servletResponse.containsHeader(headerName))
+      return;
     String headerValue = header.getValue();
     if (headerName.equalsIgnoreCase(org.apache.http.cookie.SM.SET_COOKIE) ||
             headerName.equalsIgnoreCase(org.apache.http.cookie.SM.SET_COOKIE2)) {