diff --git a/extmod/mbedtls/mbedtls_config_common.h b/extmod/mbedtls/mbedtls_config_common.h
index 252f293e03..9ec2af8553 100644
--- a/extmod/mbedtls/mbedtls_config_common.h
+++ b/extmod/mbedtls/mbedtls_config_common.h
@@ -45,7 +45,6 @@
 #define MBEDTLS_ECP_DP_BP256R1_ENABLED
 #define MBEDTLS_ECP_DP_BP384R1_ENABLED
 #define MBEDTLS_ECP_DP_BP512R1_ENABLED
-#define MBEDTLS_ECP_DP_CURVE25519_ENABLED
 #define MBEDTLS_KEY_EXCHANGE_RSA_ENABLED
 // #define MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED // enabling this currently breaks ssl_data.py test
 #define MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED