diff --git a/prism/src/prism/Model.java b/prism/src/prism/Model.java
index e2d3f6ad..acf2f6e0 100644
--- a/prism/src/prism/Model.java
+++ b/prism/src/prism/Model.java
@@ -94,7 +94,7 @@ public interface Model
 	int getNumDDRowVars();
 	int getNumDDColVars();
 	int getNumDDVarsInTrans();
-	Vector getDDVarNames();
+	Vector<String> getDDVarNames();
 	
 	ODDNode getODD();