diff --git a/scripts/config.py b/scripts/config.py
index ae0614a..b60f93d 100755
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -185,6 +185,7 @@
     'MBEDTLS_PKCS11_C', # build dependency (libpkcs11-helper)
     'MBEDTLS_PLATFORM_NO_STD_FUNCTIONS', # removes a feature
     'MBEDTLS_PSA_CRYPTO_CONFIG', # toggles old/new style PSA config
+    'MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG', # behavior change + build dependency
     'MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER', # incompatible with USE_PSA_CRYPTO
     'MBEDTLS_PSA_CRYPTO_SPM', # platform dependency (PSA SPM)
     'MBEDTLS_PSA_INJECT_ENTROPY', # build dependency (hook functions)