diff --git a/stats.js b/stats.js
index 66ca458..67801f4 100644
--- a/stats.js
+++ b/stats.js
@@ -85,7 +85,7 @@ function mode(vals) {
     // multi-modal
     if (rank.length == vals.length) {
       // all values are modes
-      return vals
+      return new Set(vals)
     }
     var modes = new Set([mode])
     var modeCount = dist[mode]
diff --git a/test/index.js b/test/index.js
index cd54fae..5ed3cfe 100644
--- a/test/index.js
+++ b/test/index.js
@@ -81,6 +81,10 @@ test("mode", function (t) {
 
   t.deepEquals(mode([1, 2, 2, 2, 3, 14]), 2, "mode works")
 
+  t.deepEquals(mode([1, 2]), new Set([1, 2]), "all values are modes works")
+
+  t.deepEquals(mode([1, 2, 3, 4]), new Set([1, 2, 3, 4]), "all values are modes works")
+
   t.deepEquals(mode([1, 1, 7, 5, 5, 8, 7]), new Set([1, 5, 7]), "multi-modal works")
 
   t.deepEquals(mode([1, 1, 7, 5, 5, 8, 7]), new Set([1, 7, 5]), "multi-modal works and order doesn't matter (yay Set)")