diff --git a/src/onehot.jl b/src/onehot.jl
index f8061063..f94fb93e 100644
--- a/src/onehot.jl
+++ b/src/onehot.jl
@@ -42,7 +42,14 @@ function onehot(l, labels)
   OneHotVector(i, length(labels))
 end
 
-onehotbatch(ls, labels) = OneHotMatrix(length(labels), [onehot(l, labels) for l in ls])
+function onehot(l, labels, unk)
+  i = findfirst(labels, l)
+  i > 0 || return onehot(unk, labels)
+  OneHotVector(i, length(labels))
+end
+
+onehotbatch(ls, labels, unk...) =
+  OneHotMatrix(length(labels), [onehot(l, labels, unk...) for l in ls])
 
 argmax(y::AbstractVector, labels = 1:length(y)) =
   labels[findfirst(y, maximum(y))]