diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/Order.java b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/Order.java
index 5d5d80ee1..f29cdc25c 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/Order.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/Order.java
@@ -206,6 +206,9 @@ public class Order extends OrderLineGroup {
     }
 
     public void incrementLastOrderElementSequenceCode() {
+        if (this.lastOrderElementSequenceCode == null) {
+            this.lastOrderElementSequenceCode = 0;
+        }
         this.lastOrderElementSequenceCode++;
     }
 
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLine.java b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLine.java
index cb6e06dc7..e4754ef1f 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLine.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLine.java
@@ -499,6 +499,9 @@ public class OrderLine extends OrderElement {
     }
 
     public void incrementLastHoursGroupSequenceCode() {
+        if(lastHoursGroupSequenceCode==null){
+            lastHoursGroupSequenceCode = 0;
+        }
         lastHoursGroupSequenceCode++;
     }