diff --git a/R/CreateInputsModel.GRiwrm.R b/R/CreateInputsModel.GRiwrm.R
index 115916133134eee00fa8783bdb8234d88c67e920..d3c6bfd091651b2af6283a3a14092df6f0d87408 100644
--- a/R/CreateInputsModel.GRiwrm.R
+++ b/R/CreateInputsModel.GRiwrm.R
@@ -352,7 +352,7 @@ CreateOneGRiwrmInputsModel <- function(id, griwrm, ..., Qobs, Qmin, IsHyst) {
     InputsModel$Qmin <- Qmin
   } else if(np$Reservoir) {
     # If an upstream node is ungauged then we are in an ungauged reduced network
-    InputsModel$isUngauged <- any(griwrm$model[griwrm$id == griwrm$id[UpstreamNodeRows]] == "Ungauged")
+    InputsModel$isUngauged <- any(griwrm$model[griwrm$id %in% griwrm$id[UpstreamNodeRows]] == "Ungauged")
     InputsModel$Qrelease <- Qobs[, id]
   }
   return(InputsModel)