diff --git a/R/PipeOpSmote.R b/R/PipeOpSmote.R
index 9524df701..c42ab1e51 100644
--- a/R/PipeOpSmote.R
+++ b/R/PipeOpSmote.R
@@ -87,7 +87,13 @@ PipeOpSmote = R6Class("PipeOpSmote",
 
     .train_task = function(task) {
       assert_true(all(task$feature_types$type == "numeric"))
-      cols = private$.select_cols(task)
+      cols = task$feature_names
+
+      unsupported_cols = setdiff(unlist(task$col_roles), union(cols, task$target_names))
+      if (length(unsupported_cols)) {
+        stopf("SMOTE cannot generate synthetic data for the following columns since they are neither features nor targets: '%s'",
+              paste(unsupported_cols, collapse = "', '"))
+      }
 
       if (!length(cols)) {
         return(task)
@@ -102,7 +108,7 @@ PipeOpSmote = R6Class("PipeOpSmote",
       # rename target column and fix character conversion
       st[["class"]] = as_factor(st[["class"]], levels = task$class_names)
       setnames(st, "class", task$target_names)
-      
+
       task$rbind(st)
     }
   )