diff --git a/.github/workflows/check_ci.yaml b/.github/workflows/check_ci.yaml
index b81d34cc..dd0e5dbd 100644
--- a/.github/workflows/check_ci.yaml
+++ b/.github/workflows/check_ci.yaml
@@ -1,12 +1,10 @@
 name: CI Build
 
 on:
-  push:
-    branches-ignore:
-      - "main"
+  pull_request:
 
 jobs:
-  run_unit_tests:
+  run-unit-tests:
     runs-on: ubuntu-latest
 
     steps:
@@ -18,7 +16,7 @@ jobs:
        uses: exasol/python-toolbox/.github/actions/python-environment@0.13.0
        with:
          python-version: "3.10"
-         poetry-version: '1.8.2'
+         poetry-version: "1.8.2"
 
      - name: Run Unit Tests
        run: >
@@ -28,14 +26,14 @@ jobs:
          --override-ini=log_cli_level=INFO
          test/unit
 
-  run_integration_tests:
+  run-integration-tests:
     name: Integration Tests
     environment: AWS_CI_TESTS
     runs-on: ubuntu-latest
-    needs: run_unit_tests
+    needs: run-unit-tests
 
     steps:
-     - uses: actions/checkout@v3
+     - uses: actions/checkout@v4
        with:
          fetch-depth: 0
 
@@ -61,8 +59,7 @@ jobs:
        uses: exasol/python-toolbox/.github/actions/python-environment@0.13.0
        with:
          python-version: "3.10"
-         poetry-version: '1.8.2'
-
+         poetry-version: "1.8.2"
 
      - name: Run Integration Tests
        run: >
@@ -76,15 +73,23 @@ jobs:
          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_ACCESS_KEY_SECRET }}
          AWS_DEFAULT_REGION: ${{ secrets.AWS_REGION }}
 
-  run_notebook_tests:
+  approval-for-notebook-tests:
+    name: Run Jupyter Notebook Tests?
+    runs-on: ubuntu-latest
+    steps:
+      - name: Detect Running Notebook Tests
+        run: true
+    environment:
+      approve-test-execution
+
+  run-notebook-tests:
     name: Jupyter Notebook Tests
-    if: "contains(github.event.head_commit.message, '[run-notebook-tests]')"
     environment: AWS_SAGEMAKER
     runs-on: ubuntu-latest
-    needs: run_unit_tests
+    needs: approval-for-notebook-tests
 
     steps:
-     - uses: actions/checkout@v3
+     - uses: actions/checkout@v4
        with:
          fetch-depth: 0
 
@@ -110,8 +115,7 @@ jobs:
        uses: exasol/python-toolbox/.github/actions/python-environment@0.13.0
        with:
          python-version: "3.10"
-         poetry-version: '1.8.2'
-
+         poetry-version: "1.8.2"
 
      - name: Run notebook tests
        run: >
@@ -127,3 +131,11 @@ jobs:
          SAAS_HOST: ${{ secrets.INTEGRATION_TEAM_SAAS_STAGING_HOST }}
          SAAS_ACCOUNT_ID: ${{ secrets.INTEGRATION_TEAM_SAAS_STAGING_ACCOUNT_ID }}
          SAAS_PAT: ${{ secrets.INTEGRATION_TEAM_SAAS_STAGING_PAT }}
+
+  gate-2:
+    name: Gate 2 - Allow Merge
+    runs-on: ubuntu-latest
+    needs: [ run-unit-tests, run-integration-tests, run-notebook-tests ]
+    steps:
+      - name: Branch Protection
+        run: true
diff --git a/doc/changes/changelog.md b/doc/changes/changelog.md
index 783b43d2..8b3b0ca0 100644
--- a/doc/changes/changelog.md
+++ b/doc/changes/changelog.md
@@ -1,6 +1,6 @@
 # Changes
 
-* [2.1.0](changes_2.1.0.md)
+* [unreleased](unreleased.md)
 * [2.0.0](changes_2.0.0.md)
 * [1.0.0](changes_1.0.0.md)
 * [0.2.0](changes_0.2.0.md)
diff --git a/doc/changes/changes_2.1.0.md b/doc/changes/unreleased.md
similarity index 95%
rename from doc/changes/changes_2.1.0.md
rename to doc/changes/unreleased.md
index 1bf4ea0a..4b63b64d 100644
--- a/doc/changes/changes_2.1.0.md
+++ b/doc/changes/unreleased.md
@@ -35,3 +35,4 @@ n/a
 * #267: Switched CodeBuildWaiter to use tenacity
 * #276: Started using the new ITDE Manager interface in the notebook-connector 0.2.9
 * #282: Updated python version to Python 3.10
+* #295: Made notebook-tests mandatory for merge 
diff --git a/doc/developer_guide/ci.md b/doc/developer_guide/ci.md
index 4c753814..948dc3fd 100644
--- a/doc/developer_guide/ci.md
+++ b/doc/developer_guide/ci.md
@@ -3,20 +3,16 @@
 The project has two types of CI tests:
 * Unit tests and integration tests which run in a Github workflow
 * Special integration tests verifying the content of the Jupyter notebook files
-* A system test which runs on a AWS Codebuild
+* A system test which runs in a AWS Codebuild
 
 All these tests need to pass before the approval of a Github PR.
 The Github workflow will run on each push to a branch in the Github repository.
 
-However, the notebook tests and the AWS Codebuild will only run after you push a commit containing a special string in the commit message, see the following sections.
+However, the notebook tests and the AWS Codebuild will only run under specific conditions, e.g. manual approval or push a commit containing a special string in the commit message, see the following sections.
 
-### Executing Notebook Tests
+### Executing Jupyter Notebook Tests
 
-Use the following git commands to execute the notebook tests:
-
-```shell
-git commit -m "[run-notebook-tests]" --allow-empty && git push
-```
+The regular CI build will ask for confirmation (aka. "review") before executing these tests, see [ETAJ developer guide](https://github.com/exasol/exasol-test-setup-abstraction-java/blob/main/doc/developer_guide/developer_guide.md#ci-build) for details.
 
 ### Executing AWS CodeBuild