diff --git a/core/ISmmPlugin.h b/core/ISmmPlugin.h
index a738929..d15dfc5 100644
--- a/core/ISmmPlugin.h
+++ b/core/ISmmPlugin.h
@@ -40,8 +40,12 @@
 #include <ISmmPluginExt.h>
 
 #ifndef META_NO_HL2SDK
+#if SOURCE_ENGINE == SE_DOTA
+#include <interfaces/interfaces.h>
+#else
 #include <tier1/interface.h>
 #endif
+#endif
 
 class IServerPluginCallbacks;