diff --git a/module-client/src/main/java/org/apache/http/client/protocol/RequestAddCookies.java b/module-client/src/main/java/org/apache/http/client/protocol/RequestAddCookies.java
index fc2635da7..1aa8211aa 100644
--- a/module-client/src/main/java/org/apache/http/client/protocol/RequestAddCookies.java
+++ b/module-client/src/main/java/org/apache/http/client/protocol/RequestAddCookies.java
@@ -146,7 +146,7 @@ public class RequestAddCookies implements HttpRequestInterceptor {
         // Get an instance of the selected cookie policy
         CookieSpec cookieSpec = registry.getCookieSpec(policy, request.getParams());
         // Get all cookies available in the HTTP state
-        List<Cookie> cookies = cookieStore.getCookies();
+        List<Cookie> cookies = new ArrayList<Cookie>(cookieStore.getCookies());
         // Find cookies matching the given origin
         List<Cookie> matchedCookies = new ArrayList<Cookie>();
         for (Cookie cookie : cookies) {