diff --git a/DESCRIPTION b/DESCRIPTION
index 3394a24178da497241f28fe833107d7cf295be9d..a4634f7faf889ee44e3a7bcb7cfa695174ac0a0a 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: airGR
 Type: Package
 Title: Suite of GR Hydrological Models for Precipitation-Runoff Modelling
-Version: 1.4.4.21
+Version: 1.4.4.22
 Date: 2020-04-20
 Authors@R: c(
   person("Laurent", "Coron", role = c("aut", "trl"), comment = c(ORCID = "0000-0002-1503-6204")),
diff --git a/NAMESPACE b/NAMESPACE
index ca4215164d83a918e6b4c7ed980ed7ec2ad65ae4..65d8f01c5dd35e1a9b9363bbb9a9ed346222c00f 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -9,6 +9,10 @@ useDynLib(airGR, .registration = TRUE)
 ##            S3 methods           ##
 #####################################
 S3method("plot", "OutputsModel")
+S3method("SeriesAggreg2", "InputsModel")
+S3method("SeriesAggreg2", "OutputsModel")
+S3method("SeriesAggreg2", "default")
+
 
 
 
@@ -62,6 +66,10 @@ export(TransfoParam_Lag)
 export(plot.OutputsModel)
 exportPattern(".FortranOutputs")
 exportPattern(".ErrorCrit")
+exportMethods(SeriesAggreg2.InputsModel)
+exportMethods(SeriesAggreg2.OutputsModel)
+exportMethods(SeriesAggreg2.default)
+
 
 
 
diff --git a/R/SeriesAggreg2.R b/R/SeriesAggreg2.R
index d3745c7a4b1567ccdf5e4d74eb01203e4cba0644..52412a2da4b1ce6e9f31d433e944076ea688ab4c 100644
--- a/R/SeriesAggreg2.R
+++ b/R/SeriesAggreg2.R
@@ -38,7 +38,7 @@ SeriesAggreg2 <- function(TabSeries, Format, TimeFormat, NewTimeFormat, ConvertF
   ## check TabSeries other columns (boolean converted to numeric)
   apply(TabSeries[, -1L], MARGIN = 2, FUN = function(iCol) {
     if (!is.numeric(iCol)) {
-      stop("'TabSeries' columns (other than the first one) be of numeric class")
+      stop("'TabSeries' columns (other than the first one) must be of numeric class")
     }
   })
   ## check Format