diff --git a/16.0.Dockerfile b/16.0.Dockerfile
index 9887cef7..b41dbc3b 100644
--- a/16.0.Dockerfile
+++ b/16.0.Dockerfile
@@ -133,7 +133,7 @@ RUN build_deps=" \
         pydevd-odoo \
         git+https://github.com/mailgun/flanker.git@v0.9.15#egg=flanker[validator] \
         geoip2 \
-        "git-aggregator<3.0.0" \
+        "git-aggregator==4.0" \
         inotify \
         pdfminer.six \
         pg_activity \
diff --git a/17.0.Dockerfile b/17.0.Dockerfile
index fc0d4dcf..432cf503 100644
--- a/17.0.Dockerfile
+++ b/17.0.Dockerfile
@@ -133,7 +133,7 @@ RUN build_deps=" \
         pydevd-odoo \
         git+https://github.com/mailgun/flanker.git@v0.9.15#egg=flanker[validator] \
         geoip2 \
-        "git-aggregator<3.0.0" \
+        "git-aggregator==4.0" \
         inotify \
         pdfminer.six \
         pg_activity \
diff --git a/tests/__init__.py b/tests/__init__.py
index 541054bb..684288ea 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -721,8 +721,8 @@ def test_repo_merge_aggregate_permissions(self):
                     UID=str(os.getuid()),
                     GID=str(os.getgid()),
                 ),
-                # prepare repos.yaml to be non fast forward
-                ("/opt/odoo/custom/build.d/099-git_merge_no_ff",),
+                # create a fake odoo git repo to ensure a merge commit is created
+                ("/opt/odoo/custom/build.d/099-create-fake-odoo",),
                 # autoaggregate as odoo:odoo to check if merges also work
                 ("autoaggregate",),
                 (
diff --git a/tests/scaffoldings/repo_merge/custom/build.d/099-create-fake-odoo b/tests/scaffoldings/repo_merge/custom/build.d/099-create-fake-odoo
new file mode 100755
index 00000000..85995f55
--- /dev/null
+++ b/tests/scaffoldings/repo_merge/custom/build.d/099-create-fake-odoo
@@ -0,0 +1,19 @@
+#!/bin/bash
+rm -rf /tmp/fake-odoo
+mkdir /tmp/fake-odoo
+cd /tmp/fake-odoo
+
+git init
+touch odoo-bin
+git add odoo-bin
+git commit -m odoo-bin
+
+git checkout -b branch1
+touch 1.txt
+git add 1.txt
+git commit -m 1.txt
+
+git checkout -b branch2 HEAD~1
+touch 2.txt
+git add 2.txt
+git commit -m 2.txt
diff --git a/tests/scaffoldings/repo_merge/custom/build.d/099-git_merge_no_ff b/tests/scaffoldings/repo_merge/custom/build.d/099-git_merge_no_ff
deleted file mode 100755
index 6e6ecc63..00000000
--- a/tests/scaffoldings/repo_merge/custom/build.d/099-git_merge_no_ff
+++ /dev/null
@@ -1,10 +0,0 @@
-#!/bin/bash
-set -e
-# configure git for odoo to merge without fast forward to test config for merge commits in autoaggregate
-su --shell="$SHELL" odoo -c 'git config --global merge.ff false'
-su --shell="$SHELL" odoo -c 'git config --global pull.ff false'
-
-# prepare a forced merge by using an OCB version that is one commit behind the ODOO_VERSION branch
-OCB_VERSION_ONE_BEHIND=$(curl -s "https://api.github.com/repos/OCA/OCB/commits?page=2&per_page=1&sha=$ODOO_VERSION" | python -c 'import json, sys; print(json.loads("".join([l for l in sys.stdin]))[0]["sha"])')
-# shellcheck disable=SC2016
-sed -i 's/\$ODOO_VERSION^1/'"$OCB_VERSION_ONE_BEHIND"'/' /opt/odoo/custom/src/repos.yaml
diff --git a/tests/scaffoldings/repo_merge/custom/src/repos.yaml b/tests/scaffoldings/repo_merge/custom/src/repos.yaml
index c04e6692..fcb83956 100644
--- a/tests/scaffoldings/repo_merge/custom/src/repos.yaml
+++ b/tests/scaffoldings/repo_merge/custom/src/repos.yaml
@@ -3,10 +3,7 @@
   defaults:
     depth: $DEPTH_MERGE
   remotes:
-    ocb: https://github.com/OCA/OCB.git
-  target: ocb $ODOO_VERSION
+    local: /tmp/fake-odoo
   merges:
-    # $ODOO_VERSION^1 gets replaced by commit sha that is one behind $ODOO_VERSION in OCB repo by 099-git_merge_no_ff
-    # in this test, to force gitaggregate creating a merge request
-    - ocb $ODOO_VERSION^1
-    - ocb $ODOO_VERSION
+    - local branch1
+    - local branch2
diff --git a/tests/scaffoldings/repo_merge/docker-compose.yaml b/tests/scaffoldings/repo_merge/docker-compose.yaml
index de4ff6b2..909657a5 100644
--- a/tests/scaffoldings/repo_merge/docker-compose.yaml
+++ b/tests/scaffoldings/repo_merge/docker-compose.yaml
@@ -6,6 +6,7 @@ services:
       args:
         COMPILE: "false"
         ODOO_VERSION: $ODOO_MINOR
+        PIP_INSTALL_ODOO: "false" # ensure build.d/700-odoo-install does not fail
         WITHOUT_DEMO: "false"
     environment:
       PYTHONOPTIMIZE: ""