diff --git a/extensions/sdktools/vcaller.cpp b/extensions/sdktools/vcaller.cpp
index 2f008084..6603e131 100644
--- a/extensions/sdktools/vcaller.cpp
+++ b/extensions/sdktools/vcaller.cpp
@@ -186,13 +186,16 @@ static cell_t EndPrepSDKCall(IPluginContext *pContext, const cell_t *params)
 		vc = CreateValveCall(s_call_addr, s_vcalltype, s_has_return ? &s_return : NULL, s_params, s_numparams);
 	}
 
-	vc->thisinfo->decflags |= VDECODE_FLAG_BYREF;
-
 	if (!vc)
 	{
 		return BAD_HANDLE;
 	}
 
+	if (vc->thisinfo)
+	{
+		vc->thisinfo->decflags |= VDECODE_FLAG_BYREF;
+	}
+
 	Handle_t hndl = handlesys->CreateHandle(g_CallHandle, vc, pContext->GetIdentity(), myself->GetIdentity(), NULL);
 	if (!hndl)
 	{