diff --git a/gitlab/build.sh b/gitlab/build.sh
index b04d33fb8980a8f4c7cf0677801d543d7f49b7b3..3a6ea46696753fb482505b7c40d7cc8b1da007a0 100755
--- a/gitlab/build.sh
+++ b/gitlab/build.sh
@@ -19,7 +19,7 @@ else
 
 fi
 
-BOB_BUILD_NUMBER=`head -n 1 build_number.txt | tr -d '\n'`
+BOB_BUILD_NUMBER=`head -n 1 ./_ci/${OS_SLUG}/${PYTHON_VERSION}/build_number.txt | tr -d '\n'`
 export_env BOB_BUILD_NUMBER
 
 if [ -z "${CI_COMMIT_TAG}" ]; then