diff --git a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/PushAggFuncIntoStandaloneAggregateRule.java b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/PushAggFuncIntoStandaloneAggregateRule.java
index 0b96934..93da572 100644
--- a/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/PushAggFuncIntoStandaloneAggregateRule.java
+++ b/asterix-algebra/src/main/java/edu/uci/ics/asterix/optimizer/rules/PushAggFuncIntoStandaloneAggregateRule.java
@@ -14,6 +14,7 @@
  */
 package edu.uci.ics.asterix.optimizer.rules;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashSet;
 import java.util.LinkedList;
@@ -31,7 +32,6 @@
 import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalOperatorTag;
 import edu.uci.ics.hyracks.algebricks.core.algebra.base.LogicalVariable;
 import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression;
-import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AbstractFunctionCallExpression.FunctionKind;
 import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.AggregateFunctionCallExpression;
 import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.ConstantExpression;
 import edu.uci.ics.hyracks.algebricks.core.algebra.expressions.VariableReferenceExpression;
@@ -95,7 +95,10 @@
         
         // Push the agg func into the agg op.                
         AbstractFunctionCallExpression aggOpExpr = (AbstractFunctionCallExpression) aggOp.getExpressions().get(0).getValue();
-        aggOp.getExpressions().get(0).setValue(new AggregateFunctionCallExpression(AsterixBuiltinFunctions.getAsterixFunctionInfo(aggFuncIdent), false, aggOpExpr.getArguments().get(0)));
+        List<Mutable<ILogicalExpression>> aggArgs = new ArrayList<Mutable<ILogicalExpression>>();
+        aggArgs.add(aggOpExpr.getArguments().get(0));
+        AggregateFunctionCallExpression aggFuncExpr = AsterixBuiltinFunctions.makeAggregateFunctionExpression(aggFuncIdent, aggArgs);
+        aggOp.getExpressions().get(0).setValue(aggFuncExpr);
         
         // The assign now just "renames" the variable to make sure the upstream plan still works.
         srcAssignExprRef.setValue(new VariableReferenceExpression(aggVar));