diff --git a/R/RunModel_Lag.R b/R/RunModel_Lag.R
index e98e1b867340deacf0597364dedc981bcb46249e..f1ed6a2cd40bdd147d852b25b62a3a52f53eb01a 100644
--- a/R/RunModel_Lag.R
+++ b/R/RunModel_Lag.R
@@ -84,7 +84,7 @@ RunModel_Lag <- function(InputsModel, RunOptions, Param) {
       Qupstream[1:LengthTs] * HUTRANS[2, upstream_basin]
   }
   # Warning for negative flows or NAs only in extended outputs
-  if(length(RunOptions$Outputs_Sim <3)) {
+  if(length(RunOptions$Outputs_Sim) > 2) {
     if (any(OutputsModel$Qsim[!is.na(OutputsModel$Qsim)] < 0)) {
       warning(length(which(OutputsModel$Qsim < 0)), " time steps with negative flow, set to zero.")
       OutputsModel$Qsim[OutputsModel$Qsim < 0] <- 0
diff --git a/tests/testthat/test-RunModel_Lag.R b/tests/testthat/test-RunModel_Lag.R
index b3eca0417b91edfb8ba46d30801ff449dc3a3509..0432fa091351418eaa4bfeee93a906dd805183f6 100644
--- a/tests/testthat/test-RunModel_Lag.R
+++ b/tests/testthat/test-RunModel_Lag.R
@@ -97,11 +97,17 @@ test_that("'Qupstream' contain NA values", {
                                                   InputsModel = InputsModel,
                                                   IndPeriod_Run = Ind_Run))
   InputsModel$OutputsModel <- OutputsGR4JOnly
-
+  # Warning with RunModel
   expect_warning(
     RunModel_Lag(InputsModel = InputsModel, RunOptions = RunOptions, Param = 1),
     regexp = "time steps with NA values"
   )
+  # No warning during calibration
+  RunOptions$Outputs_Sim <- RunOptions$Outputs_Cal
+  expect_warning(
+    RunModel_Lag(InputsModel = InputsModel, RunOptions = RunOptions, Param = 1),
+    regexp = NA
+  )
 })
 
 test_that("Upstream basin with nil area should return same Qdown as GR4J alone", {