diff --git a/core/src/main/java/org/hibernate/dialect/Oracle8iDialect.java b/core/src/main/java/org/hibernate/dialect/Oracle8iDialect.java
index b41cd24b48..15c0ba86fe 100644
--- a/core/src/main/java/org/hibernate/dialect/Oracle8iDialect.java
+++ b/core/src/main/java/org/hibernate/dialect/Oracle8iDialect.java
@@ -121,7 +121,7 @@ public class Oracle8iDialect extends Dialect {
 		registerFunction( "current_time", new NoArgSQLFunction("current_timestamp", Hibernate.TIME, false) );
 		registerFunction( "current_timestamp", new NoArgSQLFunction("current_timestamp", Hibernate.TIMESTAMP, false) );
 
-		registerFunction( "lastday", new StandardSQLFunction("lastday", Hibernate.DATE) );
+		registerFunction( "last_day", new StandardSQLFunction("last_day", Hibernate.DATE) );
 		registerFunction( "sysdate", new NoArgSQLFunction("sysdate", Hibernate.DATE, false) );
 		registerFunction( "systimestamp", new NoArgSQLFunction("systimestamp", Hibernate.TIMESTAMP, false) );
 		registerFunction( "uid", new NoArgSQLFunction("uid", Hibernate.INTEGER, false) );
diff --git a/core/src/main/java/org/hibernate/dialect/Oracle9Dialect.java b/core/src/main/java/org/hibernate/dialect/Oracle9Dialect.java
index 4e53be006a..9ae9b2ecfa 100644
--- a/core/src/main/java/org/hibernate/dialect/Oracle9Dialect.java
+++ b/core/src/main/java/org/hibernate/dialect/Oracle9Dialect.java
@@ -103,7 +103,7 @@ public class Oracle9Dialect extends Dialect {
 		registerFunction( "current_time", new NoArgSQLFunction("current_timestamp", Hibernate.TIME, false) );
 		registerFunction( "current_timestamp", new NoArgSQLFunction("current_timestamp", Hibernate.TIMESTAMP, false) );
 		
-		registerFunction( "lastday", new StandardSQLFunction("lastday", Hibernate.DATE) );
+		registerFunction( "last_day", new StandardSQLFunction("last_day", Hibernate.DATE) );
 		registerFunction( "sysdate", new NoArgSQLFunction("sysdate", Hibernate.DATE, false) );
 		registerFunction( "systimestamp", new NoArgSQLFunction("systimestamp", Hibernate.TIMESTAMP, false) );
 		registerFunction( "uid", new NoArgSQLFunction("uid", Hibernate.INTEGER, false) );