diff --git a/src/services/BaseEntityService.ts b/src/services/BaseEntityService.ts
index 392c81e..e26a49e 100644
--- a/src/services/BaseEntityService.ts
+++ b/src/services/BaseEntityService.ts
@@ -411,6 +411,18 @@ export default abstract class BaseEntityService extends TaskManager {
     query<T extends IClrEntity, TR>(m: IModel<T, TR>,
             queryFunction?: keyof TR,
             ... args: any[]): Query<T> {
+        let entityKey;
+        if (args.length) {
+            const first = args[0];
+            if (first) {
+                const { $key, $type } = first;
+                if ($key && $type) {
+                    // this is an entity, and must be sent as an entity key
+                    entityKey = $key;
+                    args.splice(0, 1);
+                }
+            }
+        }
         return new Query({
             service: this,
             name: m.name,
diff --git a/src/services/Query.ts b/src/services/Query.ts
index 78355ea..3e986c4 100644
--- a/src/services/Query.ts
+++ b/src/services/Query.ts
@@ -128,6 +128,7 @@ interface IQueryContext {
     traceQuery?: boolean;
     queryFunction?: string;
     args?: any[];
+    entityKey?: string;
     queryProcessor?: "DotNet" | "JavaScript"
 }
 
@@ -324,6 +325,7 @@ export default class Query<T> {
             name,
             service,
             queryFunction,
+            entityKey,
             args
         } = this.context;
 
@@ -347,6 +349,9 @@ export default class Query<T> {
         if (queryFunction) {
             fm.append("function", queryFunction);
             fm.append("args", JSON.stringify(args ?? "[]"));
+            if (entityKey) {
+                fm.append("entityKey", entityKey);
+            }
         }
         if (expandable) {
             fm.append("expandable", "1");
@@ -369,7 +374,8 @@ export default class Query<T> {
                     trace,
                     expandable: expandable ? 1 : void 0,
                     function: queryFunction || void 0,
-                    args: queryFunction ? args : void 0
+                    args: queryFunction ? args : void 0,
+                    entityKey: entityKey ?? void 0
                 })
                 .asJson();
             // @ts-expect-error