diff --git a/core/clang/config.mk b/core/clang/config.mk
index a269839..4685514 100644
--- a/core/clang/config.mk
+++ b/core/clang/config.mk
@@ -3,6 +3,12 @@
 LLVM_PREBUILTS_PATH := $(LLVM_PREBUILTS_BASE)/$(BUILD_OS)-x86/$(LLVM_PREBUILTS_VERSION)/bin
 LLVM_RTLIB_PATH := $(LLVM_PREBUILTS_PATH)/../lib64/clang/$(LLVM_RELEASE_VERSION)/lib/linux/
 
+# These will come from Soong, drop the environment versions
+unexport CLANG
+unexport CLANG_CXX
+unexport CCC_CC
+unexport CCC_CXX
+
 CLANG_TBLGEN := $(BUILD_OUT_EXECUTABLES)/clang-tblgen$(BUILD_EXECUTABLE_SUFFIX)
 LLVM_TBLGEN := $(BUILD_OUT_EXECUTABLES)/llvm-tblgen$(BUILD_EXECUTABLE_SUFFIX)