diff --git a/scripts/bisect b/scripts/bisect
index 346633b68e..00b82a3299 100755
--- a/scripts/bisect
+++ b/scripts/bisect
@@ -27,7 +27,7 @@ cat > $runscript <<'EOF'
 
 build_fs () (
   set -e
-  unset CC CXX CPPFLAGS CFLAGS CXXFLAGS LDFLAGS CCACHE_DIR V VERBOSE
+  unset CC CXX CPPFLAGS CFLAGS CXXFLAGS LDFLAGS V VERBOSE
   export V=1 VERBOSE=1
   git clean -fdx
   git reset --hard HEAD