diff --git a/server/modules/routing/schemarouter/schemaroutersession.cc b/server/modules/routing/schemarouter/schemaroutersession.cc
index 6e3ac02ee..9cc287eb7 100644
--- a/server/modules/routing/schemarouter/schemaroutersession.cc
+++ b/server/modules/routing/schemarouter/schemaroutersession.cc
@@ -45,7 +45,7 @@ SchemaRouterSession::SchemaRouterSession(MXS_SESSION* session,
     , m_backends(backends)
     , m_config(router->m_config)
     , m_router(router)
-    , m_shard(m_router->m_shard_manager.get_shard(m_client->user, m_config->refresh_min_interval))
+    , m_shard(m_router->m_shard_manager.get_shard(get_cache_key(), m_config->refresh_min_interval))
     , m_state(0)
     , m_sent_sescmd(0)
     , m_replied_sescmd(0)
@@ -665,7 +665,7 @@ void SchemaRouterSession::handleError(GWBUF* pMessage,
 void SchemaRouterSession::synchronize_shards()
 {
     m_router->m_stats.shmap_cache_miss++;
-    m_router->m_shard_manager.update_shard(m_shard, m_client->user);
+    m_router->m_shard_manager.update_shard(m_shard, get_cache_key());
 }
 
 /**
@@ -1784,4 +1784,19 @@ SERVER* SchemaRouterSession::get_ps_target(GWBUF* buffer, uint32_t qtype, qc_que
     }
     return rval;
 }
+
+std::string SchemaRouterSession::get_cache_key() const
+{
+    std::string key = m_client->user;
+
+    for (const auto& b : m_backends)
+    {
+        if (b->in_use())
+        {
+            key += b->name();
+        }
+    }
+
+    return key;
+}
 }
diff --git a/server/modules/routing/schemarouter/schemaroutersession.hh b/server/modules/routing/schemarouter/schemaroutersession.hh
index e554591a1..3791884ce 100644
--- a/server/modules/routing/schemarouter/schemaroutersession.hh
+++ b/server/modules/routing/schemarouter/schemaroutersession.hh
@@ -151,6 +151,7 @@ private:
     void                 synchronize_shards();
     void                 handle_mapping_reply(SSRBackend& bref, GWBUF** pPacket);
     bool                 handle_statement(GWBUF* querybuf, SSRBackend& bref, uint8_t command, uint32_t type);
+    std::string          get_cache_key() const;
 
     /** Member variables */
     bool                   m_closed;        /**< True if session closed */