diff --git a/hibernate-core/src/main/java/org/hibernate/criterion/SizeExpression.java b/hibernate-core/src/main/java/org/hibernate/criterion/SizeExpression.java
index bb7a731143..82a86ce094 100755
--- a/hibernate-core/src/main/java/org/hibernate/criterion/SizeExpression.java
+++ b/hibernate-core/src/main/java/org/hibernate/criterion/SizeExpression.java
@@ -6,6 +6,8 @@
  */
 package org.hibernate.criterion;
 
+import java.util.Locale;
+
 import org.hibernate.Criteria;
 import org.hibernate.HibernateException;
 import org.hibernate.engine.spi.TypedValue;
@@ -45,6 +47,7 @@ public class SizeExpression implements Criterion {
 				.setCondition( pk, fk );
 
 		return String.format(
+				Locale.ROOT,
 				"? %s (select count(*) from %s where %s)",
 				op,
 				cp.getTableName(),