diff --git a/ThunkLibs/GuestLibs/CMakeLists.txt b/ThunkLibs/GuestLibs/CMakeLists.txt
index be88e1d..e8a1ee3 100644
--- a/ThunkLibs/GuestLibs/CMakeLists.txt
+++ b/ThunkLibs/GuestLibs/CMakeLists.txt
@@ -81,7 +81,7 @@ function(generate NAME SOURCE_FILE)
     OUTPUT "${OUTFILE}"
     DEPENDS "${GENERATOR_EXE}"
     DEPENDS "${SOURCE_FILE}"
-    COMMAND "${GENERATOR_EXE}" "${SOURCE_FILE}" "${NAME}" "-guest" "${OUTFILE}" "${X86_DEV_ROOTFS}" ${BITNESS_FLAGS} -- -std=c++20 ${BITNESS_FLAGS2}
+    COMMAND "${GENERATOR_EXE}" "${SOURCE_FILE}" "${NAME}" "-guest" "${OUTFILE}" "${X86_DEV_ROOTFS}" ${BITNESS_FLAGS} -- -std=c++20 ${BITNESS_FLAGS2} --config=/etc/clang/gentoo-gcc-install.cfg
       # Expand compile definitions to space-separated list of -D parameters
       "$<$<BOOL:${compile_prop}>:;-D$<JOIN:${compile_prop},;-D>>"
       # Expand include directories to space-separated list of -isystem parameters