MacOS uses end2end tests. therefore extern C needed
diff --git a/test/core/end2end/end2end_tests.h b/test/core/end2end/end2end_tests.h
index b42d90b..33943a7 100644
--- a/test/core/end2end/end2end_tests.h
+++ b/test/core/end2end/end2end_tests.h
@@ -21,6 +21,10 @@
#include <grpc/grpc.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
typedef struct grpc_end2end_test_fixture grpc_end2end_test_fixture;
typedef struct grpc_end2end_test_config grpc_end2end_test_config;
@@ -74,4 +78,8 @@
void validate_host_override_string(const char* pattern, grpc_slice str,
grpc_end2end_test_config config);
+#ifdef __cplusplus
+}
+#endif
+
#endif /* GRPC_TEST_CORE_END2END_END2END_TESTS_H */