diff --git a/src/service/allocation.py b/src/service/allocation.py
index 07cd4c6..7d572a2 100644
--- a/src/service/allocation.py
+++ b/src/service/allocation.py
@@ -62,7 +62,6 @@ async def create(self, allocation: proto.CreateAllocation) -> domain.Allocation:
                 | proto.CreateRoomedAllocation
                 | proto.CreateClosedAllocation,
             ):
-
                 if not await common.check_participants_exist(
                     allocation, self._participant_repo
                 ):
diff --git a/src/utils/logger/logger.py b/src/utils/logger/logger.py
index a7e39f1..f3ad4ae 100644
--- a/src/utils/logger/logger.py
+++ b/src/utils/logger/logger.py
@@ -22,7 +22,7 @@ def __init__(self, context: str):
             raw=False,
             capture=True,
             patchers=[],
-            extra={"context": context, "correlation_id": None},
+            extra={"context": context, "correlation_id": ""},
         )
         logger_format = (
             "<green>{time:YYYY-MM-DD HH:mm:ss.SSS}</green>|"
@@ -49,25 +49,37 @@ def _finish_record(self, name: str) -> str:
     @property
     def cor_id(self) -> str | None:
         cor_id = COR_ID.get()
-        return cor_id.hex if cor_id else None
+        return cor_id.hex if cor_id is not None else ""
 
     def trace(self, message, *args, **kwargs):
-        super().trace(message, *args, correlation_id=self.cor_id, **kwargs)
+        if self.cor_id:
+            kwargs["correlation_id"] = self.cor_id
+        super().trace(message, *args, **kwargs)
 
     def debug(self, message, *args, **kwargs):
-        super().debug(message, *args, correlation_id=self.cor_id, **kwargs)
+        if self.cor_id:
+            kwargs["correlation_id"] = self.cor_id
+        super().debug(message, *args, **kwargs)
 
     def info(self, message, *args, **kwargs):
-        super().info(message, *args, correlation_id=self.cor_id, **kwargs)
+        if self.cor_id:
+            kwargs["correlation_id"] = self.cor_id
+        super().info(message, *args, **kwargs)
 
     def warning(self, message, *args, **kwargs):
-        super().warning(message, *args, correlation_id=self.cor_id, **kwargs)
+        if self.cor_id:
+            kwargs["correlation_id"] = self.cor_id
+        super().warning(message, *args, **kwargs)
 
     def error(self, message, *args, **kwargs):
-        super().error(message, *args, correlation_id=self.cor_id, **kwargs)
+        if self.cor_id:
+            kwargs["correlation_id"] = self.cor_id
+        super().error(message, *args, **kwargs)
 
     def critical(self, message, *args, **kwargs):
-        super().critical(message, *args, correlation_id=self.cor_id, **kwargs)
+        if self.cor_id:
+            kwargs["correlation_id"] = self.cor_id
+        super().critical(message, *args, **kwargs)
 
     @contextmanager
     def activity(self, name: str, with_traceback: bool = False, capture: bool = False):