diff --git a/.github/workflows/verify-public-interface.yml b/.github/workflows/verify-public-interface.yml
index b4f607957ff..0af0626a3db 100644
--- a/.github/workflows/verify-public-interface.yml
+++ b/.github/workflows/verify-public-interface.yml
@@ -19,7 +19,14 @@ jobs:
         uses: actions/checkout@v2
         with:
             fetch-depth: 0
-
+      
+      - name: Checkout through merge base
+        uses: rmacklin/fetch-through-merge-base@v0
+        with:
+          base_ref: ${{ github.event.pull_request.base.ref }}
+          head_ref: ${{ github.event.pull_request.head.sha }}
+          deepen_length: 500
+    
       - name: Build frameworks and compare interfaces
         id: build-frameworks-compare-interface
         run: |
diff --git a/StripePayments/StripePayments/Source/Internal/API Bindings/STPPaymentMethodListDeserializer.swift b/StripePayments/StripePayments/Source/Internal/API Bindings/STPPaymentMethodListDeserializer.swift
index 431782da509..79934df5d12 100644
--- a/StripePayments/StripePayments/Source/Internal/API Bindings/STPPaymentMethodListDeserializer.swift	
+++ b/StripePayments/StripePayments/Source/Internal/API Bindings/STPPaymentMethodListDeserializer.swift	
@@ -38,6 +38,7 @@ import Foundation
                 paymentMethods.append(paymentMethod)
             }
         }
+        // Modify Swift file to trigger CI
         paymentMethodsDeserializer.paymentMethods = paymentMethods
         return paymentMethodsDeserializer
     }
diff --git a/ci_scripts/api_diff/build_xcframeworks.rb b/ci_scripts/api_diff/build_xcframeworks.rb
index e1144b4b9e8..8cee0ca8ee4 100644
--- a/ci_scripts/api_diff/build_xcframeworks.rb
+++ b/ci_scripts/api_diff/build_xcframeworks.rb
@@ -6,7 +6,13 @@
 def checkout_build_generate(branch, archive_name)
   # Checkout old or new version, build and generate API JSON
   puts "Building and generating public interface from #{branch}..."
-  system("git checkout #{branch}")
+  if archive_name == "master"
+    head_ref = ENV['GITHUB_HEAD_REF']
+    commit_sha = system("git merge-base #{branch} #{head_ref}")
+    system("git checkout #{commit_sha}")
+  else 
+    system("git checkout #{branch}")
+  end
 
   system("xcodebuild clean archive \
   -quiet \
@@ -30,5 +36,5 @@ def checkout_build_generate(branch, archive_name)
 end
 
 # Run function for master and head_ref
-checkout_build_generate("master", "master")
+checkout_build_generate(ENV["GITHUB_BASE_REF"], "master")
 checkout_build_generate(ENV['GITHUB_HEAD_REF'], "new")
\ No newline at end of file