diff --git a/README.md b/README.md
index 84caa54..7c471a2 100644
--- a/README.md
+++ b/README.md
@@ -358,6 +358,10 @@ We use `pytest` to run unit tests, which you can run with:
 uv run pytest
 ```
 
+> [!TIP]
+> You can also run tests against the [bitmapist-server](https://github.com/Doist/bitmapist-server) backend instead of Redis.
+> To do this, set the `BITMAPIST_REDIS_SERVER_PATH` variable to the path of the `bitmapist-server` executable.
+
 ## Releasing new versions
 
 1. Bump version in `pyproject.toml` (or use `uv version`)
diff --git a/test/conftest.py b/test/conftest.py
index a1c8be2..092c9bb 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -37,10 +37,10 @@ def redis_server(redis_settings):
 
 
 @pytest.fixture(scope="session", autouse=True)
-def setup_redis_for_bitmapist():
-    setup_redis("default", "localhost", 6399)
-    setup_redis("default_copy", "localhost", 6399)
-    setup_redis("db1", "localhost", 6399, db=1)
+def setup_redis_for_bitmapist(redis_settings):
+    setup_redis("default", "localhost", redis_settings["port"])
+    setup_redis("default_copy", "localhost", redis_settings["port"])
+    setup_redis("db1", "localhost", redis_settings["port"], db=1)
 
 
 @pytest.fixture(autouse=True)
@@ -52,8 +52,9 @@ def start_redis_server(server_path, port):
     """Helper function starting Redis server"""
     devzero = open(os.devnull)
     devnull = open(os.devnull, "w")
+    command = get_redis_command(server_path, port)
     proc = subprocess.Popen(
-        [server_path, "--port", str(port)],
+        command,
         stdin=devzero,
         stdout=devnull,
         stderr=devnull,
@@ -63,6 +64,14 @@ def start_redis_server(server_path, port):
     return proc
 
 
+def get_redis_command(server_path, port):
+    """Run with --version to determine if this is redis or bitmapist-server"""
+    output = subprocess.check_output([server_path, "--version"])
+    if b"bitmapist-server" in output:
+        return [server_path, "-addr", f"0.0.0.0:{port}"]
+    return [server_path, "--port", str(port)]
+
+
 def is_socket_open(host, port):
     """Helper function which tests is the socket open"""
     sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)