diff --git a/test/stripe/api_resource_test.rb b/test/stripe/api_resource_test.rb
index 706801eee..948bfbbbe 100644
--- a/test/stripe/api_resource_test.rb
+++ b/test/stripe/api_resource_test.rb
@@ -314,7 +314,7 @@ class NestedTestAPIResource < APIResource
         assert_equal c.created, 12_345
       end
 
-      should "updating an object should issue a POST request with only the changed properties" do
+      should "saving an object should issue a POST request with only the changed properties" do
         stub_request(:post, "#{Stripe.api_base}/v1/customers/cus_123")
           .with(body: { "description" => "another_mn" })
           .to_return(body: JSON.generate(customer_fixture))
@@ -323,7 +323,15 @@ class NestedTestAPIResource < APIResource
         c.save
       end
 
-      should "updating should merge in returned properties" do
+      should "updating an object should issue a POST request with the specified properties" do
+        stub_request(:post, "#{Stripe.api_base}/v1/customers/cus_123")
+          .with(body: { "description" => "another_mn" })
+          .to_return(body: JSON.generate(customer_fixture))
+        Stripe::Customer.construct_from(customer_fixture)
+        Stripe::Customer.update("cus_123", { description: "another_mn" })
+      end
+
+      should "saving should merge in returned properties" do
         stub_request(:post, "#{Stripe.api_base}/v1/customers/cus_123")
           .with(body: { "description" => "another_mn" })
           .to_return(body: JSON.generate(customer_fixture))
@@ -333,14 +341,21 @@ class NestedTestAPIResource < APIResource
         assert_equal false, c.livemode
       end
 
-      should "updating should fail if api_key is overwritten with nil" do
+      should "saving should fail if api_key is overwritten with nil" do
         c = Stripe::Customer.new
         assert_raises TypeError do
           c.save({}, api_key: nil)
         end
       end
 
-      should "updating should use the supplied api_key" do
+      should "updating should fail if api_key is nil" do
+        Stripe::Customer.new("cus_123")
+        assert_raises TypeError do
+          Stripe::Customer.update("cus_123", {}, { api_key: nil })
+        end
+      end
+
+      should "saving should use the supplied api_key" do
         stub_request(:post, "#{Stripe.api_base}/v1/customers")
           .with(headers: { "Authorization" => "Bearer sk_test_local" })
           .to_return(body: JSON.generate(customer_fixture))
@@ -349,6 +364,14 @@ class NestedTestAPIResource < APIResource
         assert_equal false, c.livemode
       end
 
+      should "updating should use the supplied api_key" do
+        stub_request(:post, "#{Stripe.api_base}/v1/customers")
+          .with(headers: { "Authorization" => "Bearer sk_test_local" })
+          .to_return(body: JSON.generate(customer_fixture))
+        Stripe::Customer.new("cus_123")
+        Stripe::Customer.update("cus_123", {}, api_key: "sk_test_local")
+      end
+
       should "deleting should send no props and result in an object that has no props other deleted" do
         stub_request(:delete, "#{Stripe.api_base}/v1/customers/cus_123")
           .to_return(body: JSON.generate("id" => "cus_123", "deleted" => true))
@@ -385,7 +408,7 @@ class NestedTestAPIResource < APIResource
         c.save
       end
 
-      should "add key to nested objects" do
+      should "add key to nested objects on save" do
         acct = Stripe::Account.construct_from(id: "myid",
                                               legal_entity: {
                                                 size: "l",
@@ -401,6 +424,14 @@ class NestedTestAPIResource < APIResource
         acct.save
       end
 
+      should "update with a nested object" do
+        stub_request(:post, "#{Stripe.api_base}/v1/accounts/myid")
+          .with(body: { business_profile: { name: "Bob" } })
+          .to_return(body: JSON.generate("id" => "myid"))
+
+        Stripe::Account.update("myid", { business_profile: { name: "Bob" } })
+      end
+
       should "save nothing if nothing changes" do
         acct = Stripe::Account.construct_from(id: "acct_id",
                                               metadata: {
@@ -429,7 +460,7 @@ class NestedTestAPIResource < APIResource
         ch.save
       end
 
-      should "correctly handle replaced nested objects" do
+      should "correctly handle replaced nested objects on save" do
         acct = Stripe::Account.construct_from(
           id: "acct_123",
           company: {
@@ -449,7 +480,7 @@ class NestedTestAPIResource < APIResource
         acct.save
       end
 
-      should "correctly handle array setting" do
+      should "correctly handle array setting on save" do
         acct = Stripe::Account.construct_from(id: "myid",
                                               legal_entity: {})
 
@@ -461,7 +492,7 @@ class NestedTestAPIResource < APIResource
         acct.save
       end
 
-      should "correctly handle array insertion" do
+      should "correctly handle array insertion on save" do
         acct = Stripe::Account.construct_from(id: "myid",
                                               legal_entity: {
                                                 additional_owners: [],
@@ -478,7 +509,7 @@ class NestedTestAPIResource < APIResource
         acct.save
       end
 
-      should "correctly handle array updates" do
+      should "correctly handle array updates on save" do
         acct = Stripe::Account.construct_from(id: "myid",
                                               legal_entity: {
                                                 additional_owners: [{ first_name: "Bob" }, { first_name: "Jane" }],
@@ -495,7 +526,7 @@ class NestedTestAPIResource < APIResource
         acct.save
       end
 
-      should "correctly handle array noops" do
+      should "correctly handle array noops on save" do
         acct = Stripe::Account.construct_from(id: "myid",
                                               legal_entity: {
                                                 additional_owners: [{ first_name: "Bob" }],
@@ -509,7 +540,7 @@ class NestedTestAPIResource < APIResource
         acct.save
       end
 
-      should "correctly handle hash noops" do
+      should "correctly handle hash noops on save" do
         acct = Stripe::Account.construct_from(id: "myid",
                                               legal_entity: {
                                                 address: { line1: "1 Two Three" },