diff --git a/CHANGELOG.md b/CHANGELOG.md
index 08b123e..6e0b734 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,7 @@
 ## 1.6.x
+### 1.6.3
+#### Bugfix
+* Fix overwriting of certego field
 ### 1.6.2
 #### Bugfix
 * Added filter in routing_filter
@@ -22,7 +25,7 @@
 * Added routing history and loop protection in rule parsing
 
 ## 1.4.x
-### 1.4.1
+### 1.4.1+
 #### Bugfix
 * Updated *setup.py* to include new dependency *macaddress* 
 ### 1.4.0
diff --git a/routingfilter/routing.py b/routingfilter/routing.py
index d31e65e..2ec5b3f 100644
--- a/routingfilter/routing.py
+++ b/routingfilter/routing.py
@@ -36,8 +36,12 @@ def match(self, event: dict, type_: str = "streams", tag_field_name: str = "tags
         :return: A list of dicts containing the matched rules and the outputs in the following format: {"rules": [...], "output": {...}}; an empty list if no rule matched
         :rtype: List[dict]
         """
-        if not event.get("certego", {}).get("routing_history", {}):
-            event["certego"] = {"routing_history": {}}
+        # Creating routing_history if not present
+        if "certego" not in event:
+            event["certego"] = {}
+        if "routing_history" not in event["certego"]:
+            event["certego"]["routing_history"] = {}
+        # check for rules
         if not self.rules:
             self.logger.error("'rules_list' must be set before evaluating a match!")
             raise ValueError("'rules_list' must be set before evaluating a match!")