diff --git a/library/aes.c b/library/aes.c
index 0a61d1b..08e3caa 100644
--- a/library/aes.c
+++ b/library/aes.c
@@ -1824,6 +1824,13 @@
         } else
 #endif
 #if defined(MBEDTLS_AESNI_HAVE_CODE)
+#if MBEDTLS_AESNI_HAVE_CODE == 1
+            mbedtls_printf("  AES note: AESNI code present (assembly implementation).\n");
+#elif MBEDTLS_AESNI_HAVE_CODE == 2
+            mbedtls_printf("  AES note: AESNI code present (intrinsics implementation).\n");
+#else
+#error Unrecognised value for MBEDTLS_AESNI_HAVE_CODE
+#endif
         if (mbedtls_aesni_has_support(MBEDTLS_AESNI_AES)) {
             mbedtls_printf("  AES note: using AESNI.\n");
         } else