diff --git a/include/openssl/base.h b/include/openssl/base.h
index c8ebee8..6ea9501 100644
--- a/include/openssl/base.h
+++ b/include/openssl/base.h
@@ -202,6 +202,12 @@
 #define BORINGSSL_UNSAFE_DETERMINISTIC_MODE
 #endif
 
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+#define OPENSSL_ASAN
+#endif
+#endif
+
 /* CRYPTO_THREADID is a dummy value. */
 typedef int CRYPTO_THREADID;