diff --git a/build.sh b/build.sh
index f9a87e68a046..231b0c9f4bf8 100755
--- a/build.sh
+++ b/build.sh
@@ -26,6 +26,7 @@ while [[ $# != 0 ]]; do
 done
 
 # Build cg_clif
+unset CARGO_TARGET_DIR
 export RUSTFLAGS="-Zrun_dsymutil=no"
 if [[ "$CHANNEL" == "release" ]]; then
     cargo build --release
diff --git a/prepare.sh b/prepare.sh
index 87f96f5dcf41..08e7cb180299 100755
--- a/prepare.sh
+++ b/prepare.sh
@@ -24,6 +24,7 @@ git checkout -- .
 git checkout 804a7a21b9e673a482797aa289a18ed480e4d813
 
 # build with cg_llvm for perf comparison
+unset CARGO_TARGET_DIR
 cargo build
 mv target/debug/main raytracer_cg_llvm
 popd