diff --git a/lib/stripe/resources/customer.rb b/lib/stripe/resources/customer.rb
index 1f2c87cf3..390ebd95f 100644
--- a/lib/stripe/resources/customer.rb
+++ b/lib/stripe/resources/customer.rb
@@ -112,11 +112,11 @@ def self.search_auto_paging_each(params = {}, opts = {}, &blk)
       search(params, opts).auto_paging_each(&blk)
     end
 
-    def self.retrieve_cash_balance(customer, opts = {})
+    def self.retrieve_cash_balance(customer, params = {}, opts = {})
       request_stripe_object(
         method: :get,
         path: format("/v1/customers/%<customer>s/cash_balance", { customer: CGI.escape(customer) }),
-        params: {},
+        params: params,
         opts: opts
       )
     end
diff --git a/test/stripe/customer_test.rb b/test/stripe/customer_test.rb
index 326f54474..66070b69d 100644
--- a/test/stripe/customer_test.rb
+++ b/test/stripe/customer_test.rb
@@ -230,30 +230,22 @@ class CustomerTest < Test::Unit::TestCase
       # compatibility for existing users.
 
       context "#retrieve_cash_balance" do
-        should "legacy call pattern - retrieve_cash_balance(customer_id, nil)" do
+        should "retrieve with just ID" do
           Stripe::Customer.retrieve_cash_balance("cus_123")
           assert_requested :get, "#{Stripe.api_base}/v1/customers/cus_123/cash_balance"
         end
 
-        should "legacy call pattern - retrieve_cash_balance(customer_id, opts)" do
+        should "retrieve with custom opts" do
           # Assert that we're actually making a change by swapping out the API base.
           assert Stripe.api_base != Stripe.connect_base
 
-          Stripe::Customer.retrieve_cash_balance("cus_123", { api_base: Stripe.connect_base })
-          assert_requested :get, "#{Stripe.connect_base}/v1/customers/cus_123/cash_balance"
-        end
-
-        should "modern call pattern - retrieve_cash_balance(customer_id, opts)" do
-          # Assert that we're actually making a change by swapping out the API base.
-          assert Stripe.api_base != Stripe.connect_base
-
-          Stripe::Customer.retrieve_cash_balance("cus_123", { api_base: Stripe.connect_base })
+          Stripe::Customer.retrieve_cash_balance("cus_123", {}, { api_base: Stripe.connect_base })
           assert_requested :get, "#{Stripe.connect_base}/v1/customers/cus_123/cash_balance"
         end
       end
 
       context "#update_cash_balance" do
-        should "legacy call pattern - update_cash_balance(customer, params)" do
+        should "update with ID, params" do
           Stripe::Customer.update_cash_balance("cus_123", { settings: { reconciliation_mode: "manual" } })
 
           assert_requested :post, "#{Stripe.api_base}/v1/customers/cus_123/cash_balance" do |req|
@@ -261,7 +253,7 @@ class CustomerTest < Test::Unit::TestCase
           end
         end
 
-        should "legacy call pattern - update_cash_balance(customer, params, opts)" do
+        should "update with ID, params and opts" do
           # Assert that we're actually making a change by swapping out the API base.
           assert Stripe.api_base != Stripe.connect_base
 
@@ -276,7 +268,7 @@ class CustomerTest < Test::Unit::TestCase
           end
         end
 
-        should "modern call pattern - update_cash_balance(customer)" do
+        should "update with just ID" do
           Stripe::Customer.update_cash_balance("cus_123")
 
           assert_requested :post, "#{Stripe.api_base}/v1/customers/cus_123/cash_balance"