diff --git a/mos-platform/mega65/clang.cfg b/mos-platform/mega65/clang.cfg
index 623825078..c409f453f 100644
--- a/mos-platform/mega65/clang.cfg
+++ b/mos-platform/mega65/clang.cfg
@@ -1,3 +1,5 @@
+-isystem <CFGDIR>/../mos-platform/c64/include
+-I <CFGDIR>/../mos-platform/c64/asminc
 -mlto-zp=110
 -D__MEGA65__
 -mcpu=mos65ce02