diff --git a/scripts/config.pl b/scripts/config.pl
index 1cf1435..e5cc697 100755
--- a/scripts/config.pl
+++ b/scripts/config.pl
@@ -127,6 +127,7 @@
 MBEDTLS_RSA_NO_CRT
 MBEDTLS_SSL_HW_RECORD_ACCEL
 MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN
+MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND
 MBEDTLS_TEST_NULL_ENTROPY
 MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION
 MBEDTLS_ZLIB_SUPPORT