diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index c99460b2..986e58e7 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -5,11 +5,27 @@ on: [push, pull_request]
 jobs:
   poetry:
     runs-on: ${{ matrix.os }}
+    services:
+      postgres:
+        image: postgres:latest
+        env:
+          POSTGRES_USER: cashu
+          POSTGRES_PASSWORD: cashu
+          POSTGRES_DB: cashu
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
     strategy:
       matrix:
         os: [ubuntu-latest]
         python-version: ["3.10.4"]
         poetry-version: ["1.5.1"]
+        # db-url: ["", "postgres://cashu:cashu@localhost:5432/test"] # TODO: Postgres test not working
+        db-url: [""]
     steps:
       - name: Checkout repository and submodules
         uses: actions/checkout@v2
@@ -26,7 +42,7 @@ jobs:
           cache: "poetry"
       - name: Install dependencies
         run: |
-          poetry install
+          poetry install --extras pgsql
         shell: bash
       - name: Run tests
         env:
@@ -34,6 +50,7 @@ jobs:
           WALLET_NAME: test_wallet
           MINT_HOST: localhost
           MINT_PORT: 3337
+          MINT_DATABASE: ${{ inputs.db-url }}
           TOR: false
         run: |
           make test
diff --git a/README.md b/README.md
index c359a570..190c25b0 100644
--- a/README.md
+++ b/README.md
@@ -76,18 +76,20 @@ source ~/.bashrc
 #### Poetry: Install Cashu
 ```bash
 # install cashu
-git clone https://github.com/callebtc/cashu.git
+git clone https://github.com/cashubtc/nutshell.git cashu
 cd cashu
 pyenv local 3.10.4
 poetry install
 ```
 
+If you would like to use PostgreSQL as the mint database, use the command `poetry install --extras pgsql`.
+
 #### Poetry: Update Cashu
 To update Cashu to the newest version enter
 ```bash
 git pull && poetry install
 ```
-#### Poetry: Using Cashu
+#### Poetry: Using the Nutshell wallet
 
 Cashu should be now installed. To execute the following commands, activate your virtual Poetry environment via
 
@@ -183,11 +185,13 @@ You can find the API docs at [http://localhost:4448/docs](http://localhost:4448/
 
 # Running a mint
 This command runs the mint on your local computer. Skip this step if you want to use the [public test mint](#test-instance) instead.
+
+Before you can run your own mint, make sure to enable a Lightning backend in `MINT_LIGHTNING_BACKEND` and set `MINT_PRIVATE_KEY` in your `.env` file.
 ```bash
-python -m cashu.mint
+poetry run mint
 ```
 
-You can turn off Lightning support and mint as many tokens as you like by setting `LIGHTNING=FALSE` in the `.env` file.
+For testing, you can use Nutshell without a Lightning backend by setting `MINT_LIGHTNING_BACKEND=FakeWallet` in the `.env` file.
 
 
 # Running tests
diff --git a/cashu/mint/migrations.py b/cashu/mint/migrations.py
index c2c7a937..5b9270ba 100644
--- a/cashu/mint/migrations.py
+++ b/cashu/mint/migrations.py
@@ -183,9 +183,9 @@ async def m009_add_out_to_invoices(db: Database):
     # column in invoices for marking whether the invoice is incoming (out=False) or outgoing (out=True)
     async with db.connect() as conn:
         # we have to drop the balance views first and recreate them later
+        await conn.execute(f"DROP VIEW {table_with_schema(db, 'balance')}")
         await conn.execute(f"DROP VIEW {table_with_schema(db, 'balance_issued')}")
         await conn.execute(f"DROP VIEW {table_with_schema(db, 'balance_redeemed')}")
-        await conn.execute(f"DROP VIEW {table_with_schema(db, 'balance')}")
 
         # rename column pr to bolt11
         await conn.execute(
diff --git a/tests/conftest.py b/tests/conftest.py
index 02751323..39914079 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -57,11 +57,16 @@ async def start_mint_init(ledger: Ledger):
         await ledger.load_used_proofs()
         await ledger.init_keysets()
 
-    db_file = "test_data/mint/test.sqlite3"
-    if os.path.exists(db_file):
-        os.remove(db_file)
+    database_name = "test"
+
+    if not settings.mint_database.startswith("postgres"):
+        # clear sqlite database
+        db_file = os.path.join(settings.mint_database, database_name + ".sqlite3")
+        if os.path.exists(db_file):
+            os.remove(db_file)
+
     ledger = Ledger(
-        db=Database("test", "test_data/mint"),
+        db=Database(database_name, settings.mint_database),
         seed=settings.mint_private_key,
         derivation_path=settings.mint_derivation_path,
         lightning=FakeWallet(),