diff --git a/Dockerfile b/Dockerfile
index 661b4c9..dcaa956 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,7 +9,7 @@ ARG REPO_NAME="https://github.com/GitHK/osparc-simcore-forked.git"
 ARG BRANCH_NAME="service-integration-library-additions"
 ARG COMMIT_SHA="4973ac6123511ecb06ff039eae5e6dfc81d45179"
 ARG CLONE_DIR="/opsarc"
-ARG PYTHON_VERSION="3.8.10"
+ARG PYTHON_VERSION="3.9.12"
 ARG DEBIAN_FRONTEND=noninteractive
 ARG DOCKER_COMPOSE_VERSION="1.29.2"
 ARG INSTALL_DIR="/package-install-dir"
diff --git a/src/docker_publisher_osparc_services/cli.py b/src/docker_publisher_osparc_services/cli.py
index 0997727..8151e5b 100644
--- a/src/docker_publisher_osparc_services/cli.py
+++ b/src/docker_publisher_osparc_services/cli.py
@@ -51,6 +51,13 @@ async def run_command(config: Path) -> None:
             # check if image is present in repository
             for image in images:
                 image_name, tag = image.split(":")
+
+                if image_name in repo_model.registry.skip_images:
+                    print(
+                        f"Skipping {image_name}, used as a dependency by other images"
+                    )
+                    continue
+
                 if image_name not in repo_model.registry.local_to_test:
                     raise ValueError(
                         (
diff --git a/src/docker_publisher_osparc_services/models.py b/src/docker_publisher_osparc_services/models.py
index 8330f00..8fdfafd 100644
--- a/src/docker_publisher_osparc_services/models.py
+++ b/src/docker_publisher_osparc_services/models.py
@@ -38,6 +38,13 @@ class RegistryTargetModel(BaseModel):
             "ci/builder/osparc-sparc-internal/master/jupyter-math": "ci/osparc-sparc-internal/master/jupyter-math"
         },
     )
+    skip_images: List[str] = Field(
+        [],
+        description=(
+            "these images are only require for building and should will be "
+            "excluded when checking against local_to_test"
+        ),
+    )
 
     @root_validator()
     def validate_consistency(cls, values: Dict) -> Dict: