diff --git a/.coveragerc b/.coveragerc
index 11f2ec8387..bbf9046b06 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -1,8 +1,8 @@
 [run]
 branch = True
 parallel = True
-include=$TOP/synapse/*
-data_file = $TOP/.coverage
+include=$GITHUB_WORKSPACE/synapse/*
+data_file = $GITHUB_WORKSPACE/.coverage
 
 [report]
 precision = 2
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a04f6abbed..572bc81b0f 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -278,13 +278,7 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
-      - name: Patch Buildkite-specific test scripts
-        run: |
-          sed -i -e 's/host="postgres"/host="localhost"/' .buildkite/scripts/postgres_exec.py
-          sed -i -e 's/host: postgres/host: localhost/' .buildkite/postgres-config.yaml
-          sed -i -e 's|/src/||' .buildkite/{sqlite,postgres}-config.yaml
-          sed -i -e 's/\$TOP/\$GITHUB_WORKSPACE/' .coveragerc
-      - run: .buildkite/scripts/test_synapse_port_db.sh
+      - run: ci/scripts/test_synapse_port_db.sh
 
   complement:
     if: ${{ !failure() && !cancelled() }}
diff --git a/.buildkite/postgres-config.yaml b/ci/postgres-config.yaml
similarity index 86%
rename from .buildkite/postgres-config.yaml
rename to ci/postgres-config.yaml
index 67e17fa9d1..511fef495d 100644
--- a/.buildkite/postgres-config.yaml
+++ b/ci/postgres-config.yaml
@@ -3,7 +3,7 @@
 # CI's Docker setup at the point where this file is considered.
 server_name: "localhost:8800"
 
-signing_key_path: ".buildkite/test.signing.key"
+signing_key_path: "ci/test.signing.key"
 
 report_stats: false
 
@@ -11,7 +11,7 @@ database:
   name: "psycopg2"
   args:
     user: postgres
-    host: postgres
+    host: localhost
     password: postgres
     database: synapse
 
diff --git a/.buildkite/scripts/postgres_exec.py b/ci/scripts/postgres_exec.py
similarity index 92%
rename from .buildkite/scripts/postgres_exec.py
rename to ci/scripts/postgres_exec.py
index 086b391724..0f39a336d5 100755
--- a/.buildkite/scripts/postgres_exec.py
+++ b/ci/scripts/postgres_exec.py
@@ -23,7 +23,7 @@ import psycopg2
 # We use "postgres" as a database because it's bound to exist and the "synapse" one
 # doesn't exist yet.
 db_conn = psycopg2.connect(
-    user="postgres", host="postgres", password="postgres", dbname="postgres"
+    user="postgres", host="localhost", password="postgres", dbname="postgres"
 )
 db_conn.autocommit = True
 cur = db_conn.cursor()
diff --git a/.buildkite/scripts/test_synapse_port_db.sh b/ci/scripts/test_synapse_port_db.sh
similarity index 60%
rename from .buildkite/scripts/test_synapse_port_db.sh
rename to ci/scripts/test_synapse_port_db.sh
index 82d7d56d4e..9ee0ad42fc 100755
--- a/.buildkite/scripts/test_synapse_port_db.sh
+++ b/ci/scripts/test_synapse_port_db.sh
@@ -20,22 +20,22 @@ pip install -e .
 echo "--- Generate the signing key"
 
 # Generate the server's signing key.
-python -m synapse.app.homeserver --generate-keys -c .buildkite/sqlite-config.yaml
+python -m synapse.app.homeserver --generate-keys -c ci/sqlite-config.yaml
 
 echo "--- Prepare test database"
 
 # Make sure the SQLite3 database is using the latest schema and has no pending background update.
-scripts-dev/update_database --database-config .buildkite/sqlite-config.yaml
+scripts-dev/update_database --database-config ci/sqlite-config.yaml
 
 # Create the PostgreSQL database.
-./.buildkite/scripts/postgres_exec.py "CREATE DATABASE synapse"
+./ci/scripts/postgres_exec.py "CREATE DATABASE synapse"
 
 echo "+++ Run synapse_port_db against test database"
-coverage run scripts/synapse_port_db --sqlite-database .buildkite/test_db.db --postgres-config .buildkite/postgres-config.yaml
+coverage run scripts/synapse_port_db --sqlite-database ci/test_db.db --postgres-config ci/postgres-config.yaml
 
 # We should be able to run twice against the same database.
 echo "+++ Run synapse_port_db a second time"
-coverage run scripts/synapse_port_db --sqlite-database .buildkite/test_db.db --postgres-config .buildkite/postgres-config.yaml
+coverage run scripts/synapse_port_db --sqlite-database ci/test_db.db --postgres-config ci/postgres-config.yaml
 
 #####
 
@@ -44,14 +44,14 @@ coverage run scripts/synapse_port_db --sqlite-database .buildkite/test_db.db --p
 echo "--- Prepare empty SQLite database"
 
 # we do this by deleting the sqlite db, and then doing the same again.
-rm .buildkite/test_db.db
+rm ci/test_db.db
 
-scripts-dev/update_database --database-config .buildkite/sqlite-config.yaml
+scripts-dev/update_database --database-config ci/sqlite-config.yaml
 
 # re-create the PostgreSQL database.
-./.buildkite/scripts/postgres_exec.py \
+./ci/scripts/postgres_exec.py \
   "DROP DATABASE synapse" \
   "CREATE DATABASE synapse"
 
 echo "+++ Run synapse_port_db against empty database"
-coverage run scripts/synapse_port_db --sqlite-database .buildkite/test_db.db --postgres-config .buildkite/postgres-config.yaml
+coverage run scripts/synapse_port_db --sqlite-database ci/test_db.db --postgres-config ci/postgres-config.yaml
diff --git a/.buildkite/sqlite-config.yaml b/ci/sqlite-config.yaml
similarity index 80%
rename from .buildkite/sqlite-config.yaml
rename to ci/sqlite-config.yaml
index d16459cfd9..fd5a1c1451 100644
--- a/.buildkite/sqlite-config.yaml
+++ b/ci/sqlite-config.yaml
@@ -3,14 +3,14 @@
 # schema and run background updates on it.
 server_name: "localhost:8800"
 
-signing_key_path: ".buildkite/test.signing.key"
+signing_key_path: "ci/test.signing.key"
 
 report_stats: false
 
 database:
   name: "sqlite3"
   args:
-    database: ".buildkite/test_db.db"
+    database: "ci/test_db.db"
 
 # Suppress the key server warning.
 trusted_key_servers: []