diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/streches/StretchesFunctionModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/streches/StretchesFunctionModel.java
index a7b47b953..bc8d073b6 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/streches/StretchesFunctionModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/streches/StretchesFunctionModel.java
@@ -221,6 +221,9 @@ public class StretchesFunctionModel implements IStretchesFunctionModel {
     private static boolean theFirstIntervalIsPosteriorToFirstDay(
             List<Stretch> stretches, LocalDate start) {
         List<Interval> intervals = StretchesFunction.intervalsFor(stretches);
+        if (intervals.isEmpty()) {
+            return false;
+        }
         Interval first = intervals.get(0);
         return first.getEnd().compareTo(start) > 0;
     }