diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 35143337a703dccbd58d9e77626f3c16f9bbe242..dc13f03d5248845ef357770afe7259d39176e607 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -47,6 +47,9 @@ stages:
   # update apt
   - apt-get update
 
+  # create 'ci_deps' folder (if not exists)
+  - mkdir -pv ci_deps
+
 .license_header_template: &license_header_definition
   - cd $CI_PROJECT_DIR
 
@@ -84,9 +87,7 @@ stages:
   - fi
 
 .install_yamlschemacpp_template: &install_yamlschemacpp_definition
-  - cd $CI_PROJECT_DIR
-  - mkdir -pv ci_deps
-  - cd ci_deps
+  - cd ${CI_PROJECT_DIR}/ci_deps
   - if [ -d yaml-schema-cpp ]; then
   -   echo "directory yaml-schema-cpp exists"
   -   cd yaml-schema-cpp
@@ -131,6 +132,7 @@ build_and_test:bionic:
   image: labrobotica/wolf_deps:18.04
   script:
     - *print_variables_definition
+    - *preliminaries_definition
     - *install_yamlschemacpp_definition
     - *build_and_test_definition
 
@@ -140,6 +142,7 @@ build_and_test:focal:
   image: labrobotica/wolf_deps:20.04
   script:
     - *print_variables_definition
+    - *preliminaries_definition
     - *install_yamlschemacpp_definition
     - *build_and_test_definition