diff --git a/libreplan-webapp/src/main/java/org/libreplan/web/planner/chart/LoadChartFiller.java b/libreplan-webapp/src/main/java/org/libreplan/web/planner/chart/LoadChartFiller.java
index d00a16f55..ba236a7a9 100644
--- a/libreplan-webapp/src/main/java/org/libreplan/web/planner/chart/LoadChartFiller.java
+++ b/libreplan-webapp/src/main/java/org/libreplan/web/planner/chart/LoadChartFiller.java
@@ -38,7 +38,9 @@ public abstract class LoadChartFiller extends ChartFiller {
 
     @Override
     public void fillChart(Timeplot chart, Interval interval, Integer size) {
-        chart.getChildren().clear();
+        if (chart.getChildren() != null) {
+            chart.getChildren().clear();
+        }
         chart.invalidate();
 
         if (getOptionalJavascriptCall() != null) {