diff --git a/h2o-py/h2o/h2o.py b/h2o-py/h2o/h2o.py
index 521cba050c24..94d4f664b322 100644
--- a/h2o-py/h2o/h2o.py
+++ b/h2o-py/h2o/h2o.py
@@ -2043,6 +2043,7 @@ def make_metrics(predicted, actual, domain=None, distribution=None, weights=None
     if weights is not None:
         params["weights_frame"] = weights.frame_id
     if treatment is not None:
+        assert treatment.ncol == 1, "`treatment` frame should have exactly 1 column"
         params["treatment_frame"] = treatment.frame_id
         allowed_auuc_types = ["qini", "lift", "gain", "AUTO"]
         assert auuc_type in allowed_auuc_types, "auuc_type should be "+(" ".join([str(type) for type in allowed_auuc_types]))
diff --git a/h2o-r/h2o-package/R/models.R b/h2o-r/h2o-package/R/models.R
index f6e4d509a4d8..5f7ae8138d97 100755
--- a/h2o-r/h2o-package/R/models.R
+++ b/h2o-r/h2o-package/R/models.R
@@ -1138,7 +1138,7 @@ h2o.make_metrics <- function(predicted, actuals, domain=NULL, distribution=NULL,
   predicted <- .validate.H2OFrame(predicted, required=TRUE)
   actuals <- .validate.H2OFrame(actuals, required=TRUE)
   weights <- .validate.H2OFrame(weights, required=FALSE)
-  treatment <- .validate.H2OFrame(treatment, required=TRUE)
+  treatment <- .validate.H2OFrame(treatment, required=FALSE)
   if (!is.character(auc_type)) stop("auc_type argument must be of type character")
   if (!(auc_type %in% c("MACRO_OVO", "MACRO_OVR", "WEIGHTED_OVO", "WEIGHTED_OVR", "NONE", "AUTO"))) {
     stop("auc_type argument must be MACRO_OVO, MACRO_OVR, WEIGHTED_OVO, WEIGHTED_OVR, NONE, AUTO")
@@ -1157,8 +1157,8 @@ h2o.make_metrics <- function(predicted, actuals, domain=NULL, distribution=NULL,
       if (auuc_nbins < -1 || auuc_nbins == 0) {
         stop("auuc_nbins must be -1 or higher than 0.")
       }
-      params$auuc_type = auuc_type
-      params$auuc_nbins = auuc_nbins
+      params$auuc_type <- auuc_type
+      params$auuc_nbins <- auuc_nbins
   }
   params$domain <- domain
   params$distribution <- distribution