diff --git a/src/helma/objectmodel/db/DbMapping.java b/src/helma/objectmodel/db/DbMapping.java
index b89731ed..e16c5a08 100644
--- a/src/helma/objectmodel/db/DbMapping.java
+++ b/src/helma/objectmodel/db/DbMapping.java
@@ -89,6 +89,7 @@ public final class DbMapping implements Updatable {
     public DbMapping (Application app) {
 
 	this.app = app;
+	this.typename = null;
 
 	prop2db = new HashMap ();
 	db2prop = new HashMap ();
@@ -105,6 +106,10 @@ public final class DbMapping implements Updatable {
 
 	this.app = app;
 	this.typename = typename;
+	// create a unique instance of the string. This is useful so 
+	// we can compare types just by using == instead of equals.
+	if (typename != null)
+	    typename = typename.intern ();
 
 	prop2db = new HashMap ();
 	db2prop = new HashMap ();