diff --git a/src/java/com/samskivert/jdbc/depot/DepotMarshaller.java b/src/java/com/samskivert/jdbc/depot/DepotMarshaller.java
index 14a29bb..2915bf0 100644
--- a/src/java/com/samskivert/jdbc/depot/DepotMarshaller.java
+++ b/src/java/com/samskivert/jdbc/depot/DepotMarshaller.java
@@ -173,6 +173,10 @@ public class DepotMarshaller<T extends PersistentRecord>
                     _valueGenerators.put(
                         field.getName(), new TableValueGenerator(generator, gv, this, fm));
                     break;
+
+                case SEQUENCE: // TODO
+                    throw new IllegalArgumentException(
+                        "SEQUENCE key generation strategy not yet supported.");
                 }
             }