diff --git a/shibsp/handler/AssertionConsumerService.h b/shibsp/handler/AssertionConsumerService.h
index 45e8309..22fa143 100644
--- a/shibsp/handler/AssertionConsumerService.h
+++ b/shibsp/handler/AssertionConsumerService.h
@@ -112,7 +112,8 @@ namespace shibsp {
             const Application& application,
             const xmltooling::HTTPRequest& httpRequest,
             xmltooling::HTTPResponse& httpResponse,
-            std::string& relayState
+            std::string& relayState,
+            std::string session_id
             ) const;
 
 #ifndef SHIBSP_LITE
@@ -150,7 +151,7 @@ namespace shibsp {
          * @param reserved      ignore this parameter
          * @param xmlObject     a protocol-specific message object
          */
-        virtual void implementProtocol(
+        virtual std::string implementProtocol(
             const Application& application,
             const xmltooling::HTTPRequest& httpRequest,
             xmltooling::HTTPResponse& httpResponse,
diff --git a/shibsp/handler/impl/AssertionConsumerService.cpp b/shibsp/handler/impl/AssertionConsumerService.cpp
index 881e887..6448fc5 100644
--- a/shibsp/handler/impl/AssertionConsumerService.cpp
+++ b/shibsp/handler/impl/AssertionConsumerService.cpp
@@ -109,7 +109,7 @@ pair<bool,long> AssertionConsumerService::run(SPRequest& request, bool isHandler
             param = cgi.getParameters("target");
             if (param.first != param.second && param.first->second)
                 target = param.first->second;
-            return finalizeResponse(request.getApplication(), request, request, target);
+            return finalizeResponse(request.getApplication(), request, request, target, nullptr);
         }
     }
 
@@ -184,7 +184,7 @@ pair<bool,long> AssertionConsumerService::processMessage(
         msg.reset(m_decoder->decode(relayState, httpRequest, *(policy.get())));
         if (!msg)
             throw BindingException("Failed to decode an SSO protocol response.");
-        implementProtocol(application, httpRequest, httpResponse, *policy, nullptr, *msg);
+        string session_id = implementProtocol(application, httpRequest, httpResponse, *policy, nullptr, *msg);
 
         // History cookie.
         auto_ptr_char issuer(policy->getIssuer() ? policy->getIssuer()->getName() : nullptr);
@@ -225,7 +225,7 @@ pair<bool,long> AssertionConsumerService::processMessage(
             return make_pair(true, httpResponse.sendRedirect(hook.c_str()));
         }
 
-        return finalizeResponse(application, httpRequest, httpResponse, relayState);
+        return finalizeResponse(application, httpRequest, httpResponse, relayState, session_id);
     }
     catch (XMLToolingException& ex) {
         // Recover relay state.
@@ -295,23 +295,32 @@ pair<bool,long> AssertionConsumerService::processMessage(
 }
 
 pair<bool,long> AssertionConsumerService::finalizeResponse(
-    const Application& application, const HTTPRequest& httpRequest, HTTPResponse& httpResponse, string& relayState
+    const Application& application, const HTTPRequest& httpRequest, HTTPResponse& httpResponse, string& relayState, string session_id
     ) const
 {
     DDF postData = recoverPostData(application, httpRequest, httpResponse, relayState.c_str());
     DDFJanitor postjan(postData);
     recoverRelayState(application, httpRequest, httpResponse, relayState);
-    application.limitRedirect(httpRequest, relayState.c_str());
+
+    string dest(relayState);
+    if (dest.find('?') == string::npos)
+      dest += '?';
+    else
+      dest += '&';
+    dest += "_shibsession_=";
+    dest += session_id;
+
+    application.limitRedirect(httpRequest, dest.c_str());
 
     // Now redirect to the state value. By now, it should be set to *something* usable.
     // First check for POST data.
     if (!postData.islist()) {
-        m_log.debug("ACS returning via redirect to: %s", relayState.c_str());
-        return make_pair(true, httpResponse.sendRedirect(relayState.c_str()));
+        m_log.debug("ACS returning via redirect to: %s", dest.c_str());
+        return make_pair(true, httpResponse.sendRedirect(dest.c_str()));
     }
     else {
-        m_log.debug("ACS returning via POST to: %s", relayState.c_str());
-        return make_pair(true, sendPostResponse(application, httpResponse, relayState.c_str(), postData));
+        m_log.debug("ACS returning via POST to: %s", dest.c_str());
+        return make_pair(true, sendPostResponse(application, httpResponse, dest.c_str(), postData));
     }
 }
 
diff --git a/shibsp/handler/impl/SAML1Consumer.cpp b/shibsp/handler/impl/SAML1Consumer.cpp
index 0b663a2..98c8b97 100644
--- a/shibsp/handler/impl/SAML1Consumer.cpp
+++ b/shibsp/handler/impl/SAML1Consumer.cpp
@@ -89,7 +89,7 @@ namespace shibsp {
         }
 
     private:
-        void implementProtocol(
+        string implementProtocol(
             const Application& application,
             const HTTPRequest& httpRequest,
             HTTPResponse& httpResponse,
@@ -132,7 +132,7 @@ namespace shibsp {
 
 #ifndef SHIBSP_LITE
 
-void SAML1Consumer::implementProtocol(
+string SAML1Consumer::implementProtocol(
     const Application& application,
     const HTTPRequest& httpRequest,
     HTTPResponse& httpResponse,
@@ -353,6 +353,7 @@ void SAML1Consumer::implementProtocol(
             login_event->m_attributes = &ctx->getResolvedAttributes();
         application.getServiceProvider().getTransactionLog()->write(*login_event);
     }
+    return session_id;
 }
 
 #endif
diff --git a/shibsp/handler/impl/SAML2Consumer.cpp b/shibsp/handler/impl/SAML2Consumer.cpp
index ec62384..d525e0f 100644
--- a/shibsp/handler/impl/SAML2Consumer.cpp
+++ b/shibsp/handler/impl/SAML2Consumer.cpp
@@ -86,7 +86,7 @@ namespace shibsp {
         }
 
     private:
-        void implementProtocol(
+        string implementProtocol(
             const Application& application,
             const HTTPRequest& httpRequest,
             HTTPResponse& httpResponse,
@@ -128,7 +128,7 @@ namespace shibsp {
 
 #ifndef SHIBSP_LITE
 
-void SAML2Consumer::implementProtocol(
+string SAML2Consumer::implementProtocol(
     const Application& application,
     const HTTPRequest& httpRequest,
     HTTPResponse& httpResponse,
@@ -493,6 +493,7 @@ void SAML2Consumer::implementProtocol(
     catch (std::exception& ex) {
         m_log.warn("exception auditing event: %s", ex.what());
     }
+    return session_id;
 }
 
 #endif
diff --git a/shibsp/impl/StorageServiceSessionCache.cpp b/shibsp/impl/StorageServiceSessionCache.cpp
index 9e5d48d..b381f5e 100644
--- a/shibsp/impl/StorageServiceSessionCache.cpp
+++ b/shibsp/impl/StorageServiceSessionCache.cpp
@@ -165,6 +165,16 @@ namespace {
             }
             pair<string,const char*> shib_cookie = app.getCookieNameProps("_shibsession_");
             const char* session_id = request.getCookie(shib_cookie.first.c_str());
+            if (!session_id) {
+                // try to find it in url
+                const char* query = request.getQueryString();
+
+                session_id = query ? strstr(query, "_shibsession_=") : nullptr;
+                if (session_id) {
+                    session_id += strlen("_shibsession_=");
+                    m_log.warn("found session_id %s in url", session_id);
+                }
+            }
             return (session_id ? session_id : "");
         }