diff --git a/index.js b/index.js
index 35ac3aa..4bcf583 100644
--- a/index.js
+++ b/index.js
@@ -652,12 +652,12 @@
     return this.reduce(function(acc, x) { return f(acc, x); }, initial);
   }
 
-  //  Array$prototype$traverse :: Applicative f => Array a ~> (a -> f b, c -> f c) -> f (Array b)
-  function Array$prototype$traverse(f, of) {
+  //  Array$prototype$traverse :: Applicative f => Array a ~> (TypeRep f, a -> f b) -> f (Array b)
+  function Array$prototype$traverse(typeRep, f) {
     var xs = this;
     function go(idx, n) {
       switch (n) {
-        case 0: return of([]);
+        case 0: return of(typeRep, []);
         case 2: return lift2(pair, f(xs[idx]), f(xs[idx + 1]));
         default:
           var m = Math.floor(n / 4) * 2;
@@ -1395,7 +1395,7 @@
     return Foldable.methods.reduce(foldable)(f, x);
   }
 
-  //# traverse :: (Applicative f, Traversable t) => (a -> f a, b -> f c, t b) -> f (t c)
+  //# traverse :: (Applicative f, Traversable t) => (TypeRep f, a -> f b, t a) -> f (t b)
   //.
   //. Function wrapper for [`fantasy-land/traverse`][].
   //.
@@ -1405,19 +1405,19 @@
   //. See also [`sequence`](#sequence).
   //.
   //. ```javascript
-  //. > traverse(x => [x], x => x, [[1, 2, 3], [4, 5]])
+  //. > traverse(Array, x => x, [[1, 2, 3], [4, 5]])
   //. [[1, 4], [1, 5], [2, 4], [2, 5], [3, 4], [3, 5]]
   //.
   //. > traverse(Identity, x => Identity(x + 1), [1, 2, 3])
   //. Identity([2, 3, 4])
   //. ```
-  function traverse(of, f, traversable) {
-    return Traversable.methods.traverse(traversable)(f, of);
+  function traverse(typeRep, f, traversable) {
+    return Traversable.methods.traverse(traversable)(typeRep, f);
   }
 
-  //# sequence :: (Applicative f, Traversable t) => (a -> f a, t (f b)) -> f (t b)
+  //# sequence :: (Applicative f, Traversable t) => (TypeRep f, t (f a)) -> f (t a)
   //.
-  //. Inverts the given `t (f b)` to produce an `f (t b)`.
+  //. Inverts the given `t (f a)` to produce an `f (t a)`.
   //.
   //. This function is derived from [`traverse`](#traverse).
   //.
@@ -1428,8 +1428,8 @@
   //. > sequence(Identity, [Identity(1), Identity(2), Identity(3)])
   //. Identity([1, 2, 3])
   //. ```
-  function sequence(of, traversable) {
-    return traverse(of, identity, traversable);
+  function sequence(typeRep, traversable) {
+    return traverse(typeRep, identity, traversable);
   }
 
   //# extend :: Extend w => (w a -> b, w a) -> w b
diff --git a/package.json b/package.json
index 8918565..9943345 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,7 @@
   "devDependencies": {
     "doctest": "0.10.x",
     "eslint": "2.9.x",
-    "fantasy-land": "2.2.0",
+    "fantasy-land": "3.0.0",
     "istanbul": "0.4.x",
     "mocha": "2.x.x",
     "remember-bower": "0.1.x",
diff --git a/test/Identity.js b/test/Identity.js
index e245e6e..b6f2e28 100644
--- a/test/Identity.js
+++ b/test/Identity.js
@@ -39,7 +39,7 @@ Identity.prototype[FL.reduce] = function(f, x) {
   return f(x, this.value);
 };
 
-Identity.prototype[FL.traverse] = function(f, of) {
+Identity.prototype[FL.traverse] = function(typeRep, f) {
   return Z.map(Identity, f(this.value));
 };
 
diff --git a/test/List.js b/test/List.js
index 5cb08bc..c830687 100644
--- a/test/List.js
+++ b/test/List.js
@@ -73,10 +73,10 @@ List.prototype[FL.reduce] = function(f, x) {
     Z.reduce(f, f(x, this.head), this.tail);
 };
 
-List.prototype[FL.traverse] = function(f, of) {
+List.prototype[FL.traverse] = function(typeRep, f) {
   return this.tag === 'Nil' ?
-    of(Nil) :
-    Z.ap(Z.map(curry2(Cons), f(this.head)), Z.traverse(of, f, this.tail));
+    Z.of(typeRep, Nil) :
+    Z.ap(Z.map(curry2(Cons), f(this.head)), Z.traverse(typeRep, f, this.tail));
 };
 
 List.prototype.inspect =
diff --git a/test/index.js b/test/index.js
index 586c51d..db10dda 100644
--- a/test/index.js
+++ b/test/index.js
@@ -19,24 +19,12 @@ var Nothing = Maybe.Nothing;
 var Just = Maybe.Just;
 
 
-//  Array$of :: a -> Array a
-function Array$of(x) {
-  eq(arguments.length, Array$of.length);
-  return Z.of(Array, x);
-}
-
 //  Lazy$of :: a -> Lazy a
 function Lazy$of(x) {
   eq(arguments.length, Lazy$of.length);
   return Z.of(Lazy, x);
 }
 
-//  List$of :: a -> List a
-function List$of(x) {
-  eq(arguments.length, List$of.length);
-  return Z.of(List, x);
-}
-
 //  abs :: Number -> Number
 function abs(x) {
   eq(arguments.length, abs.length);
@@ -772,15 +760,15 @@ test('traverse', function() {
   eq(Z.traverse.length, 3);
   eq(Z.traverse.name, 'traverse');
 
-  eq(Z.traverse(Array$of, identity, []), [[]]);
-  eq(Z.traverse(Array$of, identity, [[1], [2], [3]]), [[1, 2, 3]]);
-  eq(Z.traverse(Array$of, identity, [[1, 2, 3], [4, 5]]), [[1, 4], [1, 5], [2, 4], [2, 5], [3, 4], [3, 5]]);
-  eq(Z.traverse(Array$of, identity, repeat(6)(range(10))).length, Math.pow(10, 6));
+  eq(Z.traverse(Array, identity, []), [[]]);
+  eq(Z.traverse(Array, identity, [[1], [2], [3]]), [[1, 2, 3]]);
+  eq(Z.traverse(Array, identity, [[1, 2, 3], [4, 5]]), [[1, 4], [1, 5], [2, 4], [2, 5], [3, 4], [3, 5]]);
+  eq(Z.traverse(Array, identity, repeat(6)(range(10))).length, Math.pow(10, 6));
   eq(Z.traverse(Identity, identInc, []), Identity([]));
   eq(Z.traverse(Identity, identInc, [1, 2, 3]), Identity([2, 3, 4]));
   eq(Z.traverse(Identity, identInc, Nil), Identity(Nil));
   eq(Z.traverse(Identity, identInc, Cons(1, Cons(2, Cons(3, Nil)))), Identity(Cons(2, Cons(3, Cons(4, Nil)))));
-  eq(Z.traverse(Lazy$of, Lazy$of, range(70000)).run().length, 70000);
+  eq(Z.traverse(Lazy, Lazy$of, range(70000)).run().length, 70000);
 });
 
 test('sequence', function() {
@@ -789,12 +777,12 @@ test('sequence', function() {
 
   eq(Z.sequence(Identity, []), Identity([]));
   eq(Z.sequence(Identity, [Identity(1), Identity(2), Identity(3)]), Identity([1, 2, 3]));
-  eq(Z.sequence(Array$of, Identity([])), []);
-  eq(Z.sequence(Array$of, Identity([1, 2, 3])), [Identity(1), Identity(2), Identity(3)]);
+  eq(Z.sequence(Array, Identity([])), []);
+  eq(Z.sequence(Array, Identity([1, 2, 3])), [Identity(1), Identity(2), Identity(3)]);
   eq(Z.sequence(Identity, Nil), Identity(Nil));
   eq(Z.sequence(Identity, Cons(Identity(1), Cons(Identity(2), Cons(Identity(3), Nil)))), Identity(Cons(1, Cons(2, Cons(3, Nil)))));
-  eq(Z.sequence(List$of, Identity(Nil)), Nil);
-  eq(Z.sequence(List$of, Identity(Cons(1, Cons(2, Cons(3, Nil))))), Cons(Identity(1), Cons(Identity(2), Cons(Identity(3), Nil))));
+  eq(Z.sequence(List, Identity(Nil)), Nil);
+  eq(Z.sequence(List, Identity(Cons(1, Cons(2, Cons(3, Nil))))), Cons(Identity(1), Cons(Identity(2), Cons(Identity(3), Nil))));
 });
 
 test('extend', function() {