diff --git a/components/tyk-gateway/templates/deployment-gw-repset.yaml b/components/tyk-gateway/templates/deployment-gw-repset.yaml
index 1cdea685..5095810a 100644
--- a/components/tyk-gateway/templates/deployment-gw-repset.yaml
+++ b/components/tyk-gateway/templates/deployment-gw-repset.yaml
@@ -143,8 +143,6 @@ spec:
             value: "/mnt/tyk-gateway/policies"
           - name: TYK_GW_STORAGE_MAXIDLE
             value: "1000"
-          - name: TYK_GW_OPTIMISATIONSUSEASYNCSESSIONWRITE
-            value: "true"
           - name: TYK_GW_ENABLENONTRANSACTIONALRATELIMITER
             value: "true"
           - name: TYK_GW_POLICIES_POLICYSOURCE
@@ -207,7 +205,7 @@ spec:
           - name: TYK_GW_HASHKEYS
             value: "true"
           - name: TYK_GW_HASHKEYFUNCTION
-            value: "murmur128"
+            value: "{{ .Values.gateway.hashKeyFunction }}"
           - name: TYK_GW_HTTPSERVEROPTIONS_ENABLEWEBSOCKETS
             value: "true"
           - name: TYK_GW_HTTPSERVEROPTIONS_MINVERSION
diff --git a/components/tyk-gateway/values.yaml b/components/tyk-gateway/values.yaml
index 4adbeb06..d9040d35 100644
--- a/components/tyk-gateway/values.yaml
+++ b/components/tyk-gateway/values.yaml
@@ -207,6 +207,8 @@ gateway:
     #      - chart-example.local
     tls: []
 
+  hashKeyFunction: murmur128
+
   # Sharding gateway allows you to selectively load APIs to specific gateways.
   # If enabled make sure you have at least one gateway that is not sharded.
   # Also be sure to match API segmentation tags with the tags selected below.