diff --git a/salt/elasticsearch/files/ingest/zeek.common b/salt/elasticsearch/files/ingest/zeek.common
index 480359335..c31625db6 100644
--- a/salt/elasticsearch/files/ingest/zeek.common
+++ b/salt/elasticsearch/files/ingest/zeek.common
@@ -12,9 +12,9 @@
     { "rename":         { "field": "message2.id.resp_h",        "target_field": "destination.ip",       "ignore_missing": true  } },
     { "rename":         { "field": "message2.id.resp_p",        "target_field": "destination.port",     "ignore_missing": true  } },
     { "set":         { "field": "client.ip",        "value": "{{source.ip}}"           } },
-    { "set":         { "if": "ctx.source.port != null", "field": "client.port",        "value": "{{source.port}}"       } },
+    { "set":         { "if": "ctx.source?.port != null", "field": "client.port",        "value": "{{source.port}}"       } },
     { "set":         { "field": "server.ip",        "value": "{{destination.ip}}"  } },
-    { "set":         { "if": "ctx.destination.port != null", "field": "server.port",        "value": "{{destination.port}}"  } },
+    { "set":         { "if": "ctx.destination?.port != null", "field": "server.port",        "value": "{{destination.port}}"  } },
     { "set":         { "field": "observer.name",        "value": "{{agent.name}}"  } },
     { "date":		{ "field": "message2.ts",	"target_field": "@timestamp",	"formats": ["ISO8601", "UNIX"], "ignore_failure": true	} },
     { "remove":		{ "field": ["agent"],	"ignore_failure": true									} },