diff --git a/codelimit/common/gsm/Pattern.py b/codelimit/common/gsm/Pattern.py
index 2a9fb4e..d52f7bf 100644
--- a/codelimit/common/gsm/Pattern.py
+++ b/codelimit/common/gsm/Pattern.py
@@ -24,6 +24,7 @@ def consume(self, item) -> State | None:
                 self.tokens.append(item)
                 self.state = transition[1]
                 return self.state
+        return None
 
     def is_accepting(self):
         return self.automata.is_accepting(self.state)
diff --git a/codelimit/common/report/ReportReader.py b/codelimit/common/report/ReportReader.py
index 54a3e3a..5547520 100644
--- a/codelimit/common/report/ReportReader.py
+++ b/codelimit/common/report/ReportReader.py
@@ -10,12 +10,12 @@
 
 class ReportReader:
     @staticmethod
-    def get_report_version(json: str) -> str:
+    def get_report_version(json: str) -> Optional[str]:
         d = loads(json)
         return d["version"] if "version" in d else None
 
     @staticmethod
-    def from_json(json: str) -> Optional[Report]:
+    def from_json(json: str) -> Report:
         d = loads(json)
         codebase = Codebase(d["root"])
         report = Report(codebase)