diff --git a/DESCRIPTION b/DESCRIPTION
index 1597c585718c9fec3ce1fd087784275bcb1e0202..a524f39e279848b12b82e7cb6c7c53fae54f81a9 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: airGR
 Type: Package
 Title: Suite of GR Hydrological Models for Precipitation-Runoff Modelling
-Version: 1.6.8.8
+Version: 1.6.8.9
 Date: 2020-11-20
 Authors@R: c(
   person("Laurent", "Coron", role = c("aut", "trl"), comment = c(ORCID = "0000-0002-1503-6204")),
diff --git a/R/SeriesAggreg2.InputsModel.R b/R/SeriesAggreg2.InputsModel.R
index 892e1377e40b9caa832239eb363e0987dffe4e25..5599e7ad70dd5bdfb5384985e3990b83e9031bba 100644
--- a/R/SeriesAggreg2.InputsModel.R
+++ b/R/SeriesAggreg2.InputsModel.R
@@ -1,14 +1,14 @@
 SeriesAggreg2.InputsModel <- function(TabSeries,
                                       Format,
-                                      TimeFormat,
-                                      NewTimeFormat,
+                                      TimeFormat = NULL,
+                                      NewTimeFormat = NULL,
                                       YearFirstMonth = 1, TimeLag = 0,
                                       verbose = TRUE, ..., simplify = FALSE) {
-  
+
   if (!inherits(TabSeries, "InputsModel")) {
     stop("to be used with 'InputsModel' object")
   }
-  
+
   res <- SeriesAggreg2.default(TabSeries = TabSeries,
                                Format = Format,
                                TimeFormat = TimeFormat,
@@ -16,11 +16,11 @@ SeriesAggreg2.InputsModel <- function(TabSeries,
                                YearFirstMonth = YearFirstMonth, TimeLag = TimeLag,
                                verbose = verbose,
                                simplify = simplify)
-  
+
   if (inherits(TabSeries, "CemaNeige")) {
     res$ZLayers <- TabSeries$ZLayers
   }
-  
+
   return(res)
 
 }
\ No newline at end of file
diff --git a/R/SeriesAggreg2.R b/R/SeriesAggreg2.R
index 2f7c4e92f7f4cb6800b6567d4a101aa99f292c04..207b92ddc94270de5429e94e78f489d817812edb 100644
--- a/R/SeriesAggreg2.R
+++ b/R/SeriesAggreg2.R
@@ -1,5 +1,5 @@
 SeriesAggreg2 <- function(TabSeries,
-                          Format, TimeFormat, NewTimeFormat,
+                          Format, TimeFormat = NULL, NewTimeFormat = NULL,
                           YearFirstMonth = 1, TimeLag = 0,
                           verbose = TRUE,
                           ...) {
@@ -7,14 +7,14 @@ SeriesAggreg2 <- function(TabSeries,
 }
 
 
-SeriesAggreg2.data.frame <- function(TabSeries, Format, TimeFormat, NewTimeFormat,
+SeriesAggreg2.data.frame <- function(TabSeries, Format, TimeFormat = NULL, NewTimeFormat = NULL,
                                   YearFirstMonth = 1, TimeLag = 0, verbose = TRUE, ..., ConvertFun) {
-  
+
   ## Arguments checks
-  if (!missing(TimeFormat)) {
+  if (!is.null(TimeFormat)) {
     warning("deprecated 'TimeFormat' argument", call. = FALSE)
   }
-  if (!missing(NewTimeFormat)) {
+  if (!is.null(NewTimeFormat)) {
     if (missing(Format)) {
       TimeStep <- c("hourly", "daily", "monthly", "yearly")
       NewTimeFormat <- match.arg(NewTimeFormat, choices = TimeStep)
@@ -88,14 +88,14 @@ SeriesAggreg2.data.frame <- function(TabSeries, Format, TimeFormat, NewTimeForma
   if (length(TimeLag) != 1 | !any(TimeLag >= 0)) {
     stop(msgTimeLag)
   }
-  
-  
+
+
   TabSeries0 <- TabSeries
   colnames(TabSeries0)[1L] <- "DatesR"
   TabSeries0$DatesR <- TabSeries0$DatesR + TimeLag
-  
+
   TabSeries2 <- TabSeries0
-  
+
   if (!Format %in% c("%d", "%m")) {
     start <- sprintf("%i-01-01 00:00:00", as.numeric(format(TabSeries2$DatesR[1L], format = "%Y"))-1)
     stop  <- sprintf("%i-12-31 00:00:00", as.numeric(format(TabSeries2$DatesR[nrow(TabSeries2)], format = "%Y"))+1)
@@ -106,10 +106,10 @@ SeriesAggreg2.data.frame <- function(TabSeries, Format, TimeFormat, NewTimeForma
     TabSeries2 <- merge(fakeTs, TabSeries2, by = "DatesR", all.x = TRUE)
   }
   TabSeries2$DatesRini <- TabSeries2$DatesR %in% TabSeries0$DatesR
-  
-  
+
+
   TabSeries2$Selec2 <- format(TabSeries2$DatesR, Format)
-  
+
     if (nchar(Format) > 2 | Format == "%Y") {
     TabSeries2$Selec <- !duplicated(TabSeries2$Selec2)
     if (all(TabSeries2$Selec)) {
@@ -133,7 +133,7 @@ SeriesAggreg2.data.frame <- function(TabSeries, Format, TimeFormat, NewTimeForma
     TabSeries2$Fac2 <- TabSeries2$Selec2
     TabSeries2$Selec <- !duplicated(TabSeries2$Selec2)
   }
-  
+
   if ("mean" %in% ConvertFun) {
     colTsAggregMean <- c("Fac2", colnames(TabSeries)[-1L][ConvertFun == "mean"])
     tsAggregMean <- aggregate(. ~ Fac2, data = TabSeries2[, colTsAggregMean], FUN = mean, na.action = na.pass)
@@ -146,13 +146,13 @@ SeriesAggreg2.data.frame <- function(TabSeries, Format, TimeFormat, NewTimeForma
   } else {
     tsAggregSum <- data.frame(a = NA, b = NA)
   }
-  
+
   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)]
   return(tsAggreg)
-  
+
 }
 
diff --git a/R/SeriesAggreg2.default.R b/R/SeriesAggreg2.default.R
index f67bc5cc34b2c8719ebe38a89dcbeb9eb7be939d..e3bb57a73410ddc8ecf7ff9a865361fb4cf3e2a3 100644
--- a/R/SeriesAggreg2.default.R
+++ b/R/SeriesAggreg2.default.R
@@ -1,16 +1,16 @@
 SeriesAggreg2.default <- function(TabSeries,
                                   Format,
-                                  TimeFormat,
-                                  NewTimeFormat,
+                                  TimeFormat = NULL,
+                                  NewTimeFormat = NULL,
                                   YearFirstMonth = 1, TimeLag = 0,
                                   verbose = TRUE, ..., simplify = FALSE) {
-  
+
   if (!inherits(TabSeries, c("InputsModel", "OutputsModel"))) {
     stop("to be used with InputsModel', or 'OutputsModel' object")
   }
-  
+
   if (!inherits(TabSeries, "GR") & inherits(TabSeries, "CemaNeige")) {
-    ClassTabSeries <- class(TabSeries) 
+    ClassTabSeries <- class(TabSeries)
     zzz <- list(zzz = rep(NaN, length(TabSeries$DatesR)))
     TabSeries <- append(TabSeries, values = zzz, after = 1)
     class(TabSeries) <- ClassTabSeries
@@ -24,7 +24,7 @@ SeriesAggreg2.default <- function(TabSeries,
       lastCol <- "Qsim"
     }
   }
-  
+
   if (inherits(TabSeries, "CemaNeige")) {
     if (inherits(TabSeries, "InputsModel")) {
       CemaNeigeLayers <- TabSeries[grep("^Layer", names(TabSeries))]
@@ -50,8 +50,8 @@ SeriesAggreg2.default <- function(TabSeries,
       res <- as.list(res)
     })
   }
-  
-  
+
+
   TabSeries2 <- TabSeries[1:which(names(TabSeries) %in% lastCol)]
   TabSeries2 <- as.data.frame.list(TabSeries2)
   NewTabSeries <- SeriesAggreg2(TabSeries = TabSeries2,
@@ -61,25 +61,25 @@ SeriesAggreg2.default <- function(TabSeries,
                                 YearFirstMonth = YearFirstMonth, TimeLag = TimeLag,
                                 verbose = verbose)
   NewTabSeries$zzz <- NULL
-  
-  
+
+
   if (simplify) {
-    
+
     return(NewTabSeries)
-    
+
   } else {
-    
+
     res <- list()
     ClassFormat <- switch(substr(Format, start = nchar(Format), stop = nchar(Format)),
                           h = "hourly",
                           d = "daily",
                           m = "monthly",
                           Y = "yearly")
-    
+
     ## to be consistent with InputsModel class and because plot.OutputsModel use the POSIXlt class
     NewTabSeries$DatesR <- as.POSIXlt(NewTabSeries$DatesR)
     res <- as.list(NewTabSeries)
-    
+
     if (inherits(TabSeries, "CemaNeige")) {
       if (inherits(TabSeries, "InputsModel")) {
         res <- c(NewTabSeries, CemaNeigeLayersAggreg)
@@ -89,10 +89,10 @@ SeriesAggreg2.default <- function(TabSeries,
       }
       # res <- append(res, CemaNeigeLayersAggreg, after = length(res))
     }
-    
+
     class(res) <- gsub("hourly|daily|monthly|yearly", ClassFormat, class(TabSeries))
     return(res)
-    
+
   }
-  
+
 }
\ No newline at end of file
diff --git a/tests/testthat/test-SeriesAggreg2.R b/tests/testthat/test-SeriesAggreg2.R
new file mode 100644
index 0000000000000000000000000000000000000000..677e2e524cfbe08fb2aab7c72bb000a54607d8ba
--- /dev/null
+++ b/tests/testthat/test-SeriesAggreg2.R
@@ -0,0 +1,14 @@
+context("SeriesAggreg2")
+
+test_that("No warning with InputsModel Cemaneige'", {
+  ## load of catchment data
+  data(L0123002)
+  ## preparation of the InputsModel object
+  InputsModel <- CreateInputsModel(FUN_MOD = RunModel_CemaNeige, DatesR = BasinObs$DatesR,
+                                   Precip = BasinObs$P,TempMean = BasinObs$T,
+                                   ZInputs = BasinInfo$HypsoData[51], HypsoData=BasinInfo$HypsoData,
+                                   NLayers = 5)
+  expect_warning(
+    SeriesAggreg2(InputsModel, "%m"),
+    regexp = NA)
+})