diff --git a/app/repositories/fake.py b/app/repositories/fake.py
new file mode 100644
index 0000000..d486049
--- /dev/null
+++ b/app/repositories/fake.py
@@ -0,0 +1,10 @@
+from __future__ import annotations
+
+
+class FakeRepository:
+    def save(self, password: str) -> None:
+        ...
+
+    @classmethod
+    def get_instance(cls) -> FakeRepository:
+        return FakeRepository()
diff --git a/app/repositories/type.py b/app/repositories/type.py
new file mode 100644
index 0000000..e0d74b6
--- /dev/null
+++ b/app/repositories/type.py
@@ -0,0 +1,6 @@
+from typing import Protocol
+
+
+class Repository(Protocol):
+    def save(self, password: str) -> None:
+        ...
diff --git a/app/usecases/pass_gen.py b/app/usecases/pass_gen.py
index a1b2797..8b5b02d 100644
--- a/app/usecases/pass_gen.py
+++ b/app/usecases/pass_gen.py
@@ -4,7 +4,7 @@ from typing import Protocol
 
 from pydantic import BaseModel
 
-from app.repositories.sqlite import PasswordRepository
+from app.repositories.type import Repository
 
 
 class PassGenOptions(BaseModel):
@@ -14,7 +14,7 @@ class PassGenOptions(BaseModel):
     numbers: bool = True
 
 
-def generate_password(repo: PasswordRepository, options: PassGenOptions) -> str:
+def generate_password(repo: Repository, options: PassGenOptions) -> str:
     characters = _build_characters(symbols=options.symbols, numbers=options.numbers)
     random_generator = _new_random_generator(options.seed)
     password = "".join(random_generator.sample(characters, options.length))
diff --git a/tests/pass_gen_test.py b/tests/pass_gen_test.py
index b2358b8..140d29e 100644
--- a/tests/pass_gen_test.py
+++ b/tests/pass_gen_test.py
@@ -1,6 +1,10 @@
 import pytest
+
+from app.repositories.fake import FakeRepository
 from app.usecases.pass_gen import PassGenOptions, generate_password
 
+fake_repo = FakeRepository.get_instance()
+
 
 @pytest.mark.parametrize(
     ("seed", "expected"),
@@ -11,7 +15,7 @@ from app.usecases.pass_gen import PassGenOptions, generate_password
 )
 def test_can_generate_random_password(seed: int, expected: str) -> None:
     options = PassGenOptions(seed=seed)
-    assert generate_password(options) == expected
+    assert generate_password(fake_repo, options) == expected
 
 
 @pytest.mark.parametrize(
@@ -23,7 +27,7 @@ def test_can_generate_random_password(seed: int, expected: str) -> None:
 )
 def test_control_password_length(seed: int, length: int, expected: str) -> None:
     options = PassGenOptions(seed=seed, length=length)
-    assert generate_password(options) == expected
+    assert generate_password(fake_repo, options) == expected
 
 
 @pytest.mark.parametrize(
@@ -35,7 +39,7 @@ def test_control_password_length(seed: int, length: int, expected: str) -> None:
 )
 def test_password_can_contain_symbols(seed: int, symbols: bool, expected: str) -> None:
     options = PassGenOptions(seed=seed, symbols=symbols)
-    assert generate_password(options) == expected
+    assert generate_password(fake_repo, options) == expected
 
 
 @pytest.mark.parametrize(
@@ -47,4 +51,4 @@ def test_password_can_contain_symbols(seed: int, symbols: bool, expected: str) -
 )
 def test_password_can_contain_numbers(seed: int, numbers: bool, expected: str) -> None:
     options = PassGenOptions(seed=seed, numbers=numbers)
-    assert generate_password(options) == expected
+    assert generate_password(fake_repo, options) == expected