diff --git a/infra/base-images/base-builder/compile b/infra/base-images/base-builder/compile
index 6d0528307..02b0cd100 100755
--- a/infra/base-images/base-builder/compile
+++ b/infra/base-images/base-builder/compile
@@ -44,7 +44,7 @@ echo "CXXFLAGS=$CXXFLAGS"
 echo "---------------------------------------------------------------"
 
 BUILD_CMD="bash -eux $SRC/build.sh"
-if [ -n "${BUILD_UID-}" -a "$BUILD_ID" -ne "0"]; then
+if [ -n "${BUILD_UID-}" -a "${BUILD_UID-}" -ne "0"]; then
   adduser -u $BUILD_UID --disabled-password --gecos '' builder
   chown -R builder $SRC $OUT $WORK
   su -c "$BUILD_CMD" builder