diff --git a/R/CreateInputsModel.R b/R/CreateInputsModel.R
index 9ee5d4c6671c85b9b5c5934da3ef7e8c967b0871..e025c85173c24a0083ad94a311244e21e26f967a 100644
--- a/R/CreateInputsModel.R
+++ b/R/CreateInputsModel.R
@@ -216,7 +216,8 @@ CreateInputsModel <- function(FUN_MOD,
     if(any(LengthHydro > 1000)) {
       warning("The unit of 'LengthHydro' has changed from m to km in v1.7 of airGR: values superior to 1000 km seem unrealistic")
     }
-    QupstrUnit <- match.arg(arg = QupstrUnit, choices = c("mm", "m3", "m3/s", "l/s", "L/s"))
+    QupstrUnit <- tolower(QupstrUnit)
+    QupstrUnit <- match.arg(arg = QupstrUnit, choices = c("mm", "m3", "m3/s", "l/s"))
   }
 
   ##check_NA_values
diff --git a/tests/testthat/test-RunModel_Lag.R b/tests/testthat/test-RunModel_Lag.R
index 3a7ed26ed25c5abc353aa303db329facdede7b4b..d5ec5ff596263c6be42a25b9cc9d74ece95e8c45 100644
--- a/tests/testthat/test-RunModel_Lag.R
+++ b/tests/testthat/test-RunModel_Lag.R
@@ -51,7 +51,7 @@ test_that("'QupstrUnit' must correspond to one possible value", {
       BasinAreas = BasinAreas,
       QupstrUnit = "m3/h"
     ),
-    regexp = "'QupstrUnit' must be one of these values: 'mm', 'm3', 'm3/s', 'L/s' or 'l/s'"
+    regexp = "'arg' should be one of “mm”, “m3”, “m3/s”, “l/s”"
   )
 })