diff --git a/dlls/rpcrt4/rpc_binding.c b/dlls/rpcrt4/rpc_binding.c
index 333de3d14cf..e42b8f9d676 100644
--- a/dlls/rpcrt4/rpc_binding.c
+++ b/dlls/rpcrt4/rpc_binding.c
@@ -819,6 +819,17 @@ RPC_STATUS WINAPI RpcBindingToStringBindingW( RPC_BINDING_HANDLE Binding, RPC_WS
   return ret;
 }
 
+/***********************************************************************
+ *             I_RpcBindingInqTransportType (RPCRT4.@)
+ */
+RPC_STATUS WINAPI I_RpcBindingInqTransportType( RPC_BINDING_HANDLE Binding, unsigned int * Type )
+{
+
+  FIXME( "(%p,%p): stub\n", Binding, Type);
+  *Type = TRANSPORT_TYPE_LPC;
+  return RPC_S_OK;
+}
+
 /***********************************************************************
  *             I_RpcBindingSetAsync (RPCRT4.@)
  * NOTES
diff --git a/dlls/rpcrt4/rpcrt4.spec b/dlls/rpcrt4/rpcrt4.spec
index bbf5a013299..95f13d8d397 100644
--- a/dlls/rpcrt4/rpcrt4.spec
+++ b/dlls/rpcrt4/rpcrt4.spec
@@ -31,7 +31,7 @@
 @ stub I_RpcBindingInqDynamicEndPointW
 @ stub I_RpcBindingInqLocalClientPID # wxp
 @ stub I_RpcBindingInqSecurityContext
-@ stub I_RpcBindingInqTransportType
+@ stdcall I_RpcBindingInqTransportType(ptr ptr)
 @ stub I_RpcBindingInqWireIdForSnego
 @ stub I_RpcBindingIsClientLocal
 # 9x version of I_RpcBindingSetAsync has 3 arguments, not 2