diff --git a/.travis.yml b/.travis.yml
index fae982ad5e..3ab667c2c6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,7 +30,7 @@ cache:
 env:
   global:
     # If changing this number, please also change it in `testing/testing.go`.
-    - STRIPE_MOCK_VERSION=0.24.0
+    - STRIPE_MOCK_VERSION=0.25.0
 
 go:
   - "1.7"
diff --git a/testing/testing.go b/testing/testing.go
index 5a7e813a86..5b7905fe2d 100644
--- a/testing/testing.go
+++ b/testing/testing.go
@@ -25,7 +25,7 @@ const (
 	// added in a more recent version of stripe-mock, we can show people a
 	// better error message instead of the test suite crashing with a bunch of
 	// confusing 404 errors or the like.
-	MockMinimumVersion = "0.24.0"
+	MockMinimumVersion = "0.25.0"
 
 	// TestMerchantID is a token that can be used to represent a merchant ID in
 	// simple tests.
diff --git a/topup/client.go b/topup/client.go
index 6b955a46a8..d631d7f4ee 100644
--- a/topup/client.go
+++ b/topup/client.go
@@ -13,6 +13,19 @@ type Client struct {
 	Key string
 }
 
+// Cancel cancels a topup.
+func Cancel(id string, params *stripe.TopupParams) (*stripe.Topup, error) {
+	return getC().Cancel(id, params)
+}
+
+// Cancel cancels a topup.
+func (c Client) Cancel(id string, params *stripe.TopupParams) (*stripe.Topup, error) {
+	path := stripe.FormatURLPath("/topups/%s/cancel", id)
+	topup := &stripe.Topup{}
+	err := c.B.Call(http.MethodPost, path, c.Key, params, topup)
+	return topup, err
+}
+
 // New creates a new topup.
 func New(params *stripe.TopupParams) (*stripe.Topup, error) {
 	return getC().New(params)
diff --git a/topup/client_test.go b/topup/client_test.go
index 896ef27624..7ed4949dd1 100644
--- a/topup/client_test.go
+++ b/topup/client_test.go
@@ -8,6 +8,12 @@ import (
 	_ "github.com/stripe/stripe-go/testing"
 )
 
+func TestTopupCancel(t *testing.T) {
+	topup, err := Cancel("tu_123", &stripe.TopupParams{})
+	assert.Nil(t, err)
+	assert.NotNil(t, topup)
+}
+
 func TestTopupGet(t *testing.T) {
 	topup, err := Get("tu_123", nil)
 	assert.Nil(t, err)