diff --git a/DESCRIPTION b/DESCRIPTION
index baffe254f5b55312e4f82dc3946b3c607bf50acd..532073eb4777877f8132c9b79922e149d8f71e4c 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: airGR
 Type: Package
 Title: Suite of GR Hydrological Models for Precipitation-Runoff Modelling
-Version: 1.4.4.27
+Version: 1.4.4.28
 Date: 2020-04-30
 Authors@R: c(
   person("Laurent", "Coron", role = c("aut", "trl"), comment = c(ORCID = "0000-0002-1503-6204")),
diff --git a/NEWS.md b/NEWS.md
index 59b12c2a61d75c9b3aa73f940ffbe7da1655912e..1b94c97b3772ee8e5ee75159d86e5c65183d6a05 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -4,7 +4,7 @@
 
 
 
-### 1.4.4.27 Release Notes (2020-04-30)
+### 1.4.4.28 Release Notes (2020-04-30)
 
 #### New features
 
diff --git a/R/SeriesAggreg2.R b/R/SeriesAggreg2.R
index 80ea4610e0f5daf19143c1bb0a9354187e08a4e8..2f7c4e92f7f4cb6800b6567d4a101aa99f292c04 100644
--- a/R/SeriesAggreg2.R
+++ b/R/SeriesAggreg2.R
@@ -141,13 +141,14 @@ SeriesAggreg2.data.frame <- function(TabSeries, Format, TimeFormat, NewTimeForma
     tsAggregMean <- data.frame(a = NA, b = NA)
   }
   if ("sum" %in% ConvertFun) {
-    colTsAggregSum <- c("Fac2", colnames(TabSeries)[-1L][ConvertFun == "sum" ])
-    tsAggregSum <- aggregate(. ~ Fac2, data = TabSeries2[, colTsAggregSum ], FUN =  sum, na.action = na.pass)
+    colTsAggregSum <- c("Fac2", colnames(TabSeries)[-1L][ConvertFun == "sum"])
+    tsAggregSum <- aggregate(. ~ Fac2, data = TabSeries2[, colTsAggregSum], FUN =  sum, na.action = na.pass)
   } else {
     tsAggregSum <- data.frame(a = NA, b = NA)
   }
   
-  tsAggreg <- cbind(tsAggregMean[, -1, drop = FALSE], tsAggregSum)
+  tsAggreg <- cbind(tsAggregMean, tsAggregSum)
+  tsAggreg <- tsAggreg[, !duplicated(colnames(tsAggreg))]
   tsAggreg <- merge(tsAggreg, TabSeries2[, c("Fac2", "DatesR", "DatesRini", "Selec")], by = "Fac2", all.x = TRUE, all.y = FALSE)
   tsAggreg <- tsAggreg[tsAggreg$Selec & tsAggreg$DatesRini, ]
   tsAggreg <- tsAggreg[, colnames(TabSeries0)]