diff --git a/backend/capellacollab/settings/modelsources/t4c/repositories/models.py b/backend/capellacollab/settings/modelsources/t4c/repositories/models.py
index e15201c16d..8f02cce72b 100644
--- a/backend/capellacollab/settings/modelsources/t4c/repositories/models.py
+++ b/backend/capellacollab/settings/modelsources/t4c/repositories/models.py
@@ -44,7 +44,7 @@ class DatabaseT4CRepository(database.Base):
 
 
 class CreateT4CRepository(pydantic.BaseModel):
-    name: str
+    name: str = pydantic.Field(pattern="/^[-a-zA-Z0-9_]+$/")
 
 
 class T4CRepositoryStatus(str, enum.Enum):