diff --git a/backend/repository/abstract_repository.py b/backend/repository/abstract_repository.py
index 14f9651..003fcbc 100644
--- a/backend/repository/abstract_repository.py
+++ b/backend/repository/abstract_repository.py
@@ -7,7 +7,7 @@ class AbstractRepository(abc.ABC):
         raise NotImplementedError
 
     @abc.abstractmethod
-    def update(self, element):
+    def update(self, reference, element):
         raise NotImplementedError
 
     @abc.abstractmethod
@@ -19,5 +19,5 @@ class AbstractRepository(abc.ABC):
         raise NotImplementedError
 
     @abc.abstractmethod
-    def delete(self, reference):
+    def delete(self, element):
         raise NotImplementedError
diff --git a/tests/model/fakes.py b/tests/model/fakes.py
index a8e2d92..314b883 100644
--- a/tests/model/fakes.py
+++ b/tests/model/fakes.py
@@ -4,6 +4,7 @@ from faker import Faker
 
 from backend.model.assessment import Assessment, Domain, Exercise, Question, Skill
 from backend.model.tribe import Tribe
+from backend.repository.abstract_repository import AbstractRepository
 
 faker = Faker()
 
@@ -66,3 +67,35 @@ def build_questions(
         ]
 
     return questions
+
+
+class FakeTribeRepository(AbstractRepository):
+    def __init__(self, tribes):
+        self._tribes = {t.name: t for t in tribes}
+
+    def add(self, tribe):
+        if tribe.name not in self._tribes.keys():
+            self._tribes[tribe.name] = tribe
+        raise KeyError(f"{tribe} already exists")
+
+    def update(self, name, tribe):
+        try:
+            self._tribes.pop(name)
+            self._tribes[tribe.name] = tribe
+        except KeyError:
+            raise KeyError(f"The tribe {tribe} does not exists")
+
+    def list(self):
+        return list(self._tribes.values())
+
+    def get(self, name):
+        try:
+            return self._tribes[name]
+        except KeyError:
+            raise KeyError(f"The tribe {tribe} does not exists")
+
+    def delete(self, name):
+        try:
+            self._tribes.pop(name)
+        except KeyError:
+            raise KeyError(f"The tribe {tribe} does not exists")