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 ed1ac7766..1dc3940ff 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
@@ -8,11 +8,11 @@ import java.util.Set;
 
 public class OrderLine extends OrderElement {
 
-    public static OrderLine createOrderLineWithUnfixedHours(int hours) {
+    public static OrderLine createOrderLineWithUnfixedPercentage(int hours) {
         OrderLine result = new OrderLine();
         HoursGroup hoursGroup = new HoursGroup();
         result.addHoursGroup(hoursGroup);
-        hoursGroup.setFixedPercentage(true);
+        hoursGroup.setFixedPercentage(false);
         hoursGroup.setPercentage(new BigDecimal(1));
         hoursGroup.setWorkingHours(hours);
         return result;
@@ -155,8 +155,13 @@ public class OrderLine extends OrderElement {
             Integer newNoFixed = workHours - newTotal;
 
             for (HoursGroup hoursGroup : noFixedGroups) {
-                Integer newHours = (int) ((float) hoursGroup.getWorkingHours()
-                        / oldNoFixed * newNoFixed);
+                Integer newHours;
+                if (oldNoFixed == 0) {
+                    newHours = (int) ((float) newNoFixed / hoursGroups.size());
+                } else {
+                    newHours = (int) ((float) hoursGroup.getWorkingHours()
+                            / oldNoFixed * newNoFixed);
+                }
                 hoursGroup.setWorkingHours(newHours);
 
                 newHoursGroups.add(hoursGroup);
diff --git a/navalplanner-business/src/test/java/org/navalplanner/business/test/orders/entities/OrderLineTest.java b/navalplanner-business/src/test/java/org/navalplanner/business/test/orders/entities/OrderLineTest.java
index 1e32d0b2b..025a9a000 100644
--- a/navalplanner-business/src/test/java/org/navalplanner/business/test/orders/entities/OrderLineTest.java
+++ b/navalplanner-business/src/test/java/org/navalplanner/business/test/orders/entities/OrderLineTest.java
@@ -580,6 +580,38 @@ public class OrderLineTest {
 
     }
 
+    /**
+     * An {@link OrderLine} with two {@link HoursGroup} of 0h NO_FIXED. Trying
+     * to set work hours of {@link OrderLine} to 200h. Expected:
+     * {@link OrderLine} with 200h. {@link HoursGroup} with 100h and
+     * {@link HoursGroup} with 100h.
+     */
+    @Test
+    public void testSetWorkHoursHoursGroupNoFixedZeroValue() {
+
+        OrderLine orderLine = new OrderLine();
+        HoursGroup hoursGroup = new HoursGroup(orderLine);
+        hoursGroup.setWorkingHours(0);
+        HoursGroup hoursGroup2 = new HoursGroup(orderLine);
+        hoursGroup2.setWorkingHours(0);
+        orderLine.addHoursGroup(hoursGroup);
+        orderLine.addHoursGroup(hoursGroup2);
+
+        assertThat(orderLine.getWorkHours(), equalTo(0));
+
+        try {
+            orderLine.setWorkHours(200);
+        } catch (IllegalArgumentException e) {
+            fail("It should not throw an exception");
+        }
+
+        assertThat(orderLine.getWorkHours(), equalTo(200));
+        assertThat(orderLine.getHoursGroups().size(), equalTo(2));
+        assertThat(hoursGroup.getWorkingHours(), equalTo(100));
+        assertThat(hoursGroup2.getWorkingHours(), equalTo(100));
+
+    }
+
     @Test
     public void testAddNewEmptyHoursGroup() {
         OrderLine orderLine = new OrderLine();
@@ -714,7 +746,7 @@ public class OrderLineTest {
         int[] hoursValues = { 0, 100, 10, 30 };
         for (int hours : hoursValues) {
             OrderLine orderLine = OrderLine
-                    .createOrderLineWithUnfixedHours(hours);
+                    .createOrderLineWithUnfixedPercentage(hours);
             assertThat(orderLine.getWorkHours(), equalTo(hours));
             assertThat(orderLine.getHoursGroups().size(), equalTo(1));
             orderLine.setWorkHours(20);
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/orders/OrderElementTreeModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/orders/OrderElementTreeModel.java
index e994cca20..ce8a6fa98 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/orders/OrderElementTreeModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/orders/OrderElementTreeModel.java
@@ -54,7 +54,7 @@ public class OrderElementTreeModel extends SimpleTreeModel {
 
     private OrderElement createNewOrderElement() {
         OrderElement newOrderElement = OrderLine
-                .createOrderLineWithUnfixedHours(0);
+                .createOrderLineWithUnfixedPercentage(0);
         newOrderElement.setName("New Order Element");
         return newOrderElement;
     }