diff --git a/scripts/config.py b/scripts/config.py
index 3d297dc..793e9df 100755
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -194,6 +194,7 @@
     'MBEDTLS_RSA_NO_CRT', # influences the use of RSA in X.509 and TLS
     'MBEDTLS_SHA512_NO_SHA384', # removes a feature
     'MBEDTLS_SSL_HW_RECORD_ACCEL', # build dependency (hook functions)
+    'MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN', # build dependency (clang+memsan)
     'MBEDTLS_TEST_NULL_ENTROPY', # removes a feature
     'MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION', # influences the use of X.509 in TLS
     'MBEDTLS_ZLIB_SUPPORT', # build dependency (libz)