diff --git a/library/constant_time_internal.h b/library/constant_time_internal.h
index a550b38..8874729 100644
--- a/library/constant_time_internal.h
+++ b/library/constant_time_internal.h
@@ -196,7 +196,7 @@
 
 #endif /* MBEDTLS_BASE64_C */
 
-#if defined(MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC)
+#if defined(MBEDTLS_SSL_SOME_SUITES_USE_MAC)
 
 /** Conditional memcpy without branches.
  *
@@ -292,7 +292,7 @@
                      size_t max_data_len,
                      unsigned char *output );
 
-#endif /* MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC */
+#endif /* MBEDTLS_SSL_SOME_SUITES_USE_MAC */
 
 #if defined(MBEDTLS_PKCS1_V15) && defined(MBEDTLS_RSA_C) && !defined(MBEDTLS_RSA_ALT)