diff --git a/enabler/src/de/schildbach/pte/dto/Trip.java b/enabler/src/de/schildbach/pte/dto/Trip.java
index 20f31a8a..4b7002a8 100644
--- a/enabler/src/de/schildbach/pte/dto/Trip.java
+++ b/enabler/src/de/schildbach/pte/dto/Trip.java
@@ -204,7 +204,7 @@ public final class Trip implements Serializable
 		return getId().hashCode();
 	}
 
-	public static class Leg implements Serializable
+	public abstract static class Leg implements Serializable
 	{
 		private static final long serialVersionUID = 8498461220084523265L;