diff --git a/libuavcan/include/uavcan/node/service_client.hpp b/libuavcan/include/uavcan/node/service_client.hpp
index db8b392dba..ce88cc1381 100644
--- a/libuavcan/include/uavcan/node/service_client.hpp
+++ b/libuavcan/include/uavcan/node/service_client.hpp
@@ -84,12 +84,15 @@ static Stream& operator<<(Stream& s, const ServiceCallResult<DataType>& scr)
  */
 class ServiceClientBase : protected DeadlineHandler
 {
+    const DataTypeDescriptor* data_type_descriptor_;  ///< This will be initialized at the time of first call
+
 protected:
     MonotonicDuration request_timeout_;
     bool pending_;
 
     explicit ServiceClientBase(INode& node)
         : DeadlineHandler(node.getScheduler())
+        , data_type_descriptor_(NULL)
         , request_timeout_(getDefaultRequestTimeout())
         , pending_(false)
     { }
@@ -159,7 +162,7 @@ private:
 
     void invokeCallback(ServiceCallResultType& result);
 
-    void handleReceivedDataStruct(ReceivedDataStructure<ResponseType>& response);
+    virtual void handleReceivedDataStruct(ReceivedDataStructure<ResponseType>& response);
 
     virtual void handleDeadline(MonotonicTime);
 
diff --git a/libuavcan/src/node/uc_service_client.cpp b/libuavcan/src/node/uc_service_client.cpp
index 773ef578cf..a0c6cc00e8 100644
--- a/libuavcan/src/node/uc_service_client.cpp
+++ b/libuavcan/src/node/uc_service_client.cpp
@@ -24,24 +24,30 @@ int ServiceClientBase::prepareToCall(INode& node, const char* dtname, NodeID ser
     /*
      * Determining the Data Type ID
      */
-    GlobalDataTypeRegistry::instance().freeze();
-    const DataTypeDescriptor* const descr = GlobalDataTypeRegistry::instance().find(DataTypeKindService, dtname);
-    if (!descr)
+    if (data_type_descriptor_ == NULL)
     {
-        UAVCAN_TRACE("ServiceClient", "Type [%s] is not registered", dtname);
-        return -ErrUnknownDataType;
+        GlobalDataTypeRegistry::instance().freeze();
+        data_type_descriptor_ = GlobalDataTypeRegistry::instance().find(DataTypeKindService, dtname);
+        if (data_type_descriptor_ == NULL)
+        {
+            UAVCAN_TRACE("ServiceClient", "Type [%s] is not registered", dtname);
+            return -ErrUnknownDataType;
+        }
+        UAVCAN_TRACE("ServiceClient", "Data type descriptor inited: %s", data_type_descriptor_->toString().c_str());
     }
+    UAVCAN_ASSERT(data_type_descriptor_ != NULL);
 
     /*
      * Determining the Transfer ID
      */
-    const OutgoingTransferRegistryKey otr_key(descr->getID(), TransferTypeServiceRequest, server_node_id);
+    const OutgoingTransferRegistryKey otr_key(data_type_descriptor_->getID(),
+                                              TransferTypeServiceRequest, server_node_id);
     const MonotonicTime otr_deadline = node.getMonotonicTime() + TransferSender::getDefaultMaxTransferInterval();
     TransferID* const otr_tid =
         node.getDispatcher().getOutgoingTransferRegistry().accessOrCreate(otr_key, otr_deadline);
     if (!otr_tid)
     {
-        UAVCAN_TRACE("ServiceClient", "OTR access failure, dtd=%s", descr->toString().c_str());
+        UAVCAN_TRACE("ServiceClient", "OTR access failure, dtd=%s", data_type_descriptor_->toString().c_str());
         return -ErrMemory;
     }
     out_transfer_id = *otr_tid;