diff --git a/src/core/tsi/test_creds/README b/src/core/tsi/test_creds/README
index ab0d851a18b..dd6a764b23c 100644
--- a/src/core/tsi/test_creds/README
+++ b/src/core/tsi/test_creds/README
@@ -67,3 +67,20 @@ Clean up:
 $ rm *.rsa
 $ rm *.csr
 $ rm ca.srl
+
+Sync up with other repositories
+===============================
+
+You will need to copy the test credentials to the following places
+grpc-dart/interop/
+grpc-dotnet/testassets/Certs/InteropTests/
+grpc-go/testdata/
+grpc-java/testing/src/main/resources/certs/
+grpc-node/test/data/
+src/csharp/Grpc.IntegrationTesting/data/
+src/objective-c/tests/TestCertificates.bundle/
+src/php/tests/data/
+src/python/grpcio_tests/tests/interop/credentials/
+src/python/grpcio_tests/tests/unit/credentials/
+src/ruby/spec/testdata/
+test/core/end2end/data/
diff --git a/src/objective-c/tests/TestCertificates.bundle/test-certificates.pem b/src/objective-c/tests/TestCertificates.bundle/test-certificates.pem
index 6c8511a73c6..49d39cd8ed5 100644
--- a/src/objective-c/tests/TestCertificates.bundle/test-certificates.pem
+++ b/src/objective-c/tests/TestCertificates.bundle/test-certificates.pem
@@ -1,15 +1,20 @@
 -----BEGIN CERTIFICATE-----
-MIICSjCCAbOgAwIBAgIJAJHGGR4dGioHMA0GCSqGSIb3DQEBCwUAMFYxCzAJBgNV
-BAYTAkFVMRMwEQYDVQQIEwpTb21lLVN0YXRlMSEwHwYDVQQKExhJbnRlcm5ldCBX
-aWRnaXRzIFB0eSBMdGQxDzANBgNVBAMTBnRlc3RjYTAeFw0xNDExMTEyMjMxMjla
-Fw0yNDExMDgyMjMxMjlaMFYxCzAJBgNVBAYTAkFVMRMwEQYDVQQIEwpTb21lLVN0
-YXRlMSEwHwYDVQQKExhJbnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQxDzANBgNVBAMT
-BnRlc3RjYTCBnzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAwEDfBV5MYdlHVHJ7
-+L4nxrZy7mBfAVXpOc5vMYztssUI7mL2/iYujiIXM+weZYNTEpLdjyJdu7R5gGUu
-g1jSVK/EPHfc74O7AyZU34PNIP4Sh33N+/A5YexrNgJlPY+E3GdVYi4ldWJjgkAd
-Qah2PH5ACLrIIC6tRka9hcaBlIECAwEAAaMgMB4wDAYDVR0TBAUwAwEB/zAOBgNV
-HQ8BAf8EBAMCAgQwDQYJKoZIhvcNAQELBQADgYEAHzC7jdYlzAVmddi/gdAeKPau
-sPBG/C2HCWqHzpCUHcKuvMzDVkY/MP2o6JIW2DBbY64bO/FceExhjcykgaYtCH/m
-oIU63+CFOTtR7otyQAWHqXa7q4SbCDlG7DyRFxqG0txPtGvy12lgldA2+RgcigQG
-Dfcog5wrJytaQ6UA0wE=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==
 -----END CERTIFICATE-----