diff --git a/api/CMakeLists.txt b/api/CMakeLists.txt
index da5deced72..10cd86865f 100644
--- a/api/CMakeLists.txt
+++ b/api/CMakeLists.txt
@@ -113,9 +113,9 @@ if(WITH_OTLP_HTTP_SSL_PREVIEW)
   endif()
 endif()
 
-if (WITH_OTLP_GRPC_MTLS_PREVIEW)
+if (WITH_OTLP_GRPC_SSL_MTLS_PREVIEW)
   target_compile_definitions(opentelemetry_api
-                             INTERFACE ENABLE_OTLP_GRPC_MTLS_PREVIEW)
+                             INTERFACE ENABLE_OTLP_GRPC_SSL_MTLS_PREVIEW)
 endif()
 
 if(WITH_METRICS_EXEMPLAR_PREVIEW)
diff --git a/exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_exporter_options.h b/exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_exporter_options.h
index 779a21aeab..01ac5b43f2 100644
--- a/exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_exporter_options.h
+++ b/exporters/otlp/include/opentelemetry/exporters/otlp/otlp_grpc_exporter_options.h
@@ -29,7 +29,7 @@ struct OtlpGrpcExporterOptions
   // SSL encryption.
   std::string ssl_credentials_cacert_as_string = GetOtlpDefaultSslCertificateString();
 
-#ifdef ENABLE_OTLP_GRPC_MTLS_PREVIEW
+#ifdef ENABLE_OTLP_GRPC_SSL_MTLS_PREVIEW
   // At most one of ssl_client_key_* should be non-empty. If use_ssl_credentials, they will
   // be read to allow for mTLS.
   std::string ssl_client_key_path   = GetOtlpDefaultTracesSslClientKeyPath();
diff --git a/exporters/otlp/src/otlp_grpc_client.cc b/exporters/otlp/src/otlp_grpc_client.cc
index a14f624d51..6952ea0422 100644
--- a/exporters/otlp/src/otlp_grpc_client.cc
+++ b/exporters/otlp/src/otlp_grpc_client.cc
@@ -69,17 +69,17 @@ std::shared_ptr<grpc::Channel> OtlpGrpcClient::MakeChannel(const OtlpGrpcExporte
   grpc_arguments.SetUserAgentPrefix(options.user_agent);
 
   if (options.use_ssl_credentials) {
-    grpc::SslCredentialsOptions ssl_opts = {
-      .pem_root_certs = GetFileContentsOrInMemoryContents(
-          options.ssl_credentials_cacert_path,
-          options.ssl_credentials_cacert_as_string),
-#if ENABLE_OTLP_GRPC_MTLS_PREVIEW
-      .pem_private_key = GetFileContentsOrInMemoryContents(
-          options.ssl_client_key_path,
-          options.ssl_client_key_string),
-      .pem_cert_chain = GetFileContentsOrInMemoryContents(
-          options.ssl_client_cert_path,
-          options.ssl_client_cert_string)
+    grpc::SslCredentialsOptions ssl_opts;
+    ssl_opts.pem_root_certs = GetFileContentsOrInMemoryContents(
+        options.ssl_credentials_cacert_path,
+        options.ssl_credentials_cacert_as_string);
+#if ENABLE_OTLP_GRPC_SSL_MTLS_PREVIEW
+    ssl_opts.pem_private_key = GetFileContentsOrInMemoryContents(
+      options.ssl_client_key_path,
+      options.ssl_client_key_string);
+    ssl_opts.pem_cert_chain = GetFileContentsOrInMemoryContents(
+      options.ssl_client_cert_path,
+      options.ssl_client_cert_string);
 #endif
     };
     channel =