diff --git a/app/otbTimeSeriesIndexTrend.cxx b/app/otbTimeSeriesIndexTrend.cxx
index e27c52258e68333cc8ee7a205bcce37014b6d9b3..192df0be1737fa7ec978443be83ad63246e916a3 100644
--- a/app/otbTimeSeriesIndexTrend.cxx
+++ b/app/otbTimeSeriesIndexTrend.cxx
@@ -382,7 +382,7 @@ private:
       {
 
         // Get the rainfall time series dates
-        std::vector<DateType> rainDates = GetTimeSeriesDates("rainfdates");
+        std::vector<DateType> rainDates = GetTimeSeriesDates(GetParameterAsString("rainfdates"));
 
         // Get the rainfall time series input images list
         FloatVectorImageListType::Pointer inRFList = this->GetParameterImageList("rainfts");