diff --git a/lsteamclient/lsteamclient.spec b/lsteamclient/lsteamclient.spec
index 4bb73815..f5ad77f8 100644
--- a/lsteamclient/lsteamclient.spec
+++ b/lsteamclient/lsteamclient.spec
@@ -56,6 +56,9 @@
 56 stub hid_write
 57 stub hid_write_output_report
 
+@ cdecl Steam_IsKnownInterface(ptr)
+@ cdecl Steam_NotifyMissingInterface(long ptr)
+
 # GameOverlayRenderer entry points
 @ stub BOverlayNeedsPresent
 @ stub IsOverlayEnabled
diff --git a/lsteamclient/steamclient_main.c b/lsteamclient/steamclient_main.c
index a5368b20..adfa4a81 100644
--- a/lsteamclient/steamclient_main.c
+++ b/lsteamclient/steamclient_main.c
@@ -828,6 +828,8 @@ static bool (*steamclient_BGetCallback)(HSteamPipe a, CallbackMsg_t *b, int32 *c
 static bool (*steamclient_GetAPICallResult)(HSteamPipe, SteamAPICall_t, void *, int, int, bool *);
 static bool (*steamclient_FreeLastCallback)(HSteamPipe);
 static void (*steamclient_ReleaseThreadLocalMemory)(int);
+static bool (*steamclient_IsKnownInterface)( const char *pchVersion );
+static void (*steamclient_NotifyMissingInterface)( HSteamPipe hSteamPipe, const char *pchVersion );
 
 static int load_steamclient(void)
 {
@@ -893,6 +895,18 @@ static int load_steamclient(void)
         return 0;
     }
 
+    steamclient_IsKnownInterface = dlsym(steamclient_lib, "Steam_IsKnownInterface");
+    if(!steamclient_IsKnownInterface){
+        ERR("unable to load IsKnownInterface method\n");
+        return 0;
+    }
+
+    steamclient_NotifyMissingInterface = dlsym(steamclient_lib, "Steam_NotifyMissingInterface");
+    if(!steamclient_NotifyMissingInterface){
+        ERR("unable to load NotifyMissingInterface method\n");
+        return 0;
+    }
+
     pthread_mutex_init(&callback_queue_mutex, NULL);
     pthread_cond_init(&callback_queue_callback_event, NULL);
     pthread_cond_init(&callback_queue_ready_event, NULL);
@@ -1112,3 +1126,17 @@ HSteamPipe after_steam_pipe_create(HSteamPipe pipe)
 
     return pipe;
 }
+
+bool Steam_IsKnownInterface( const char *pchVersion )
+{
+    TRACE("%s\n", pchVersion);
+    load_steamclient();
+    return steamclient_IsKnownInterface( pchVersion );
+}
+
+void Steam_NotifyMissingInterface( HSteamPipe hSteamPipe, const char *pchVersion )
+{
+    TRACE("%u %s\n", hSteamPipe, pchVersion);
+    load_steamclient();
+    steamclient_NotifyMissingInterface( hSteamPipe, pchVersion );
+}