diff --git a/src/Parser/__init__.py b/src/Parser/__init__.py
index bc4f79a..d42e09c 100644
--- a/src/Parser/__init__.py
+++ b/src/Parser/__init__.py
@@ -93,7 +93,7 @@ class JobShopProblem(Mapping):
     def __len__(self) -> int:
         return sum(map(len, self.problem_data))
 
-    def get_tasks_by_job(self, job):
+    def get_tasks_by_job(self, job: int) -> List[Tuple[int, int]]:
         return self.problem_data[job]
 
 class JobShopVisitor(arpeggio.PTNodeVisitor):