diff --git a/loader/AMBuilder b/loader/AMBuilder
index 13e247ee..2db3a509 100644
--- a/loader/AMBuilder
+++ b/loader/AMBuilder
@@ -13,6 +13,7 @@ binary.compiler.cxxincludes += [
   os.path.join(SM.mms_root, 'core'),
   os.path.join(SM.mms_root, 'sourcehook')
 ]
+binary.compiler.defines += ['META_NO_HL2SDK']
 if binary.compiler.family == 'gcc' or binary.compiler.family == 'clang':
   binary.compiler.cxxflags += ['-fno-rtti']
 elif binary.compiler.family == 'msvc':