diff --git a/src/foam/mlang/sink/GroupBy.js b/src/foam/mlang/sink/GroupBy.js
index 9c5e5de820..bf877d7e4e 100644
--- a/src/foam/mlang/sink/GroupBy.js
+++ b/src/foam/mlang/sink/GroupBy.js
@@ -258,12 +258,9 @@ for (Object key : getGroups().keySet()) {
       } else {
         // No explicit output type - traverse to find underlying property
         var expr = this.arg1;
-        var sourceClass = 'Unknown';
         while ( expr ) {
           if ( foam.lang.Property.isInstance(expr) ) {
             exprClass = expr.cls_?.id || 'String';
-            // Get the source class name from the property's forClass_
-            sourceClass = expr.forClass_ || sourceClass;
             break;
           }
             // Try delegate, then arg1, then stop
@@ -271,15 +268,10 @@ for (Object key : getGroups().keySet()) {
         }
       }
 
-      // Generate deterministic name based on source class, property name, and sink type
-      // This prevents conflicts in chained GroupBy operations
-      var sinkName = this.arg2.cls_?.name || 'Count';
-      var sourceClassName = sourceClass.split('.').pop(); // Get last part of class name
-      var modelName = 'GroupBy_' + sourceClassName + '_' + exprName + '_' + sinkName;
 
       const model = {
         package: 'foam.tmp',
-        name: modelName,
+        name: 'GroupBy' + foam.next$UID(),
         ids: [ 'row' ],
         properties: [
           { class: 'Long', name: 'row' },