diff --git a/DESCRIPTION b/DESCRIPTION
index 1de6906e18c1bea14ab232e5c10b7512007bc202..a0444ed6be07d550e3e5e7d27360a44a9c1b0961 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,8 +1,8 @@
 Package: airGR
 Type: Package
 Title: Suite of GR Hydrological Models for Precipitation-Runoff Modelling
-Version: 1.2.16.3
-Date: 2019-05-22
+Version: 1.2.16.4
+Date: 2019-05-24
 Authors@R: c(
   person("Laurent", "Coron", role = c("aut", "trl"), comment = c(ORCID = "0000-0002-1503-6204")),
   person("Olivier", "Delaigue", role = c("aut", "cre"), comment = c(ORCID = "0000-0002-7668-8468"), email = "airGR@irstea.fr"),
diff --git a/NEWS.rmd b/NEWS.rmd
index ee6c69e8281e8d8e01631903b968a26be02cb885..a654d363dce6f5107f240dd007c71073459238a2 100644
--- a/NEWS.rmd
+++ b/NEWS.rmd
@@ -14,7 +14,7 @@ output:
 
 
 
-### 1.2.16.3 Release Notes (2019-05-22)
+### 1.2.16.4 Release Notes (2019-05-23)
 
 
 #### New features
diff --git a/R/plot.OutputsModel.R b/R/plot.OutputsModel.R
index 007630be89466657c34fce819e28fd0305c9e9dc..7493ec7b760d748f1edc8d8700c14db29012b98d 100644
--- a/R/plot.OutputsModel.R
+++ b/R/plot.OutputsModel.R
@@ -561,6 +561,7 @@ plot.OutputsModel <- function(x, Qobs = NULL, IndPeriod_Plot = NULL, BasinArea =
   if (BOOLPLOT_Error) {
     kPlot <- kPlot + 1
     mar <- c(3, 5, 1, 5)
+    plotunitError <- "[-]"
     
     errorQ <- OutputsModel$Qsim / Qobs
     par(new = FALSE, mar = mar)
@@ -572,7 +573,7 @@ plot.OutputsModel <- function(x, Qobs = NULL, IndPeriod_Plot = NULL, BasinArea =
          xlab = "", ylab = "", log = ifelse(log_scale, "y", ""),
          panel.first = abline(h = 1, col = "grey", lty = 2), ...)
     axis(side = 2, at = pretty(ylim1), labels = pretty(ylim1), cex.axis = cex.axis, ...)
-    mtext(side = 2, paste("flow err.", plotunit), cex = cex.lab, line = line)
+    mtext(side = 2, paste("flow err.", plotunitError), cex = cex.lab, line = line)
     if (BOOL_Dates) {
       axis(side = 1, at = Seq1, labels = FALSE, cex.axis = cex.axis, ...)
       axis(side = 1, at = Seq2, labels = Labels2, lwd.ticks = 1.5, cex.axis = cex.axis, ...)