diff --git a/DESCRIPTION b/DESCRIPTION
index af836ffd1f9af99f67c3f55c02ba9480c5d951bd..3f2866c15fd691bc6a9cbedea6e5bc002cebc007 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: airGR
 Type: Package
 Title: Suite of GR Hydrological Models for Precipitation-Runoff Modelling
-Version: 1.2.15.5
+Version: 1.2.15.6
 Date: 2019-05-03
 Authors@R: c(
   person("Laurent", "Coron", role = c("aut", "trl"), comment = c(ORCID = "0000-0002-1503-6204")),
diff --git a/NEWS.rmd b/NEWS.rmd
index 9e4c3422b3f6c8275e5cc4999b4a41672352b5a5..ea556ae19724bd0a820400b2cfc211520be26ef5 100644
--- a/NEWS.rmd
+++ b/NEWS.rmd
@@ -14,7 +14,7 @@ output:
 
 
 
-### 1.2.15.5 Release Notes (2019-05-03)
+### 1.2.15.6 Release Notes (2019-05-03)
 
 
 #### New features
diff --git a/R/plot.OutputsModel.R b/R/plot.OutputsModel.R
index 9b4a2d3c59ab7f0ea69ad34ac52050e1c62a1621..ecb73e3a3b0a790c1260243fe644f0ef2e5b90d1 100644
--- a/R/plot.OutputsModel.R
+++ b/R/plot.OutputsModel.R
@@ -286,14 +286,11 @@ plot.OutputsModel <- function(x, Qobs = NULL, IndPeriod_Plot = NULL, BasinArea =
     }
     
     if (!is.null(BasinArea)) {
-      Factor_MMH_M3S <- 60 * 60
-      Factor_MMD_M3S <- 60 * 60 * 24
-      Factor_MMM_M3S <- 60 * 60 * 24 * 365.25 / 12
-      Factor_MMY_M3S <- 60 * 60 * 24 * 365.25
-      if (NameTS == "hour" ) Factor_UNIT_M3S <- Factor_MMH_M3S
-      if (NameTS == "day"  ) Factor_UNIT_M3S <- Factor_MMD_M3S
-      if (NameTS == "month") Factor_UNIT_M3S <- Factor_MMM_M3S
-      if (NameTS == "year" ) Factor_UNIT_M3S <- Factor_MMY_M3S
+      Factor_UNIT_M3S <- switch(NameTS,
+                                hour  = 60 * 60,
+                                day   = 60 * 60 * 24,
+                                month = 60 * 60 * 24 * 365.25 / 12,
+                                year  = 60 * 60 * 24 * 365.25)
       Factor_UNIT_M3S <- BasinArea / (Factor_UNIT_M3S / 1000)
     }
   }