diff --git a/lib/NGCP/Panel/Controller/API/SubscriberLocationMappings.pm b/lib/NGCP/Panel/Controller/API/SubscriberLocationMappings.pm
index 34cb2865e2..6b26da1fe8 100644
--- a/lib/NGCP/Panel/Controller/API/SubscriberLocationMappings.pm
+++ b/lib/NGCP/Panel/Controller/API/SubscriberLocationMappings.pm
@@ -22,17 +22,12 @@ sub query_params {
         {
             param => 'subscriber_id',
             description => 'Filter for location mappings of a specific subscriber',
-            query => {
-                first => sub {
-                    my $q = shift;
-                    return { 'voip_subscriber.id' => $q };
-                },
-                second => sub {
-                    return {
-                        join => { subscriber => 'voip_subscriber' }
-                    };
-                },
-            },
+            query_type => 'string_eq',
+        },
+        {
+            param => 'external_id',
+            description => 'Filter for location mappings matching the provided external_id',
+            query_type => 'string_eq',
         },
     ];
 }