diff --git a/library/ecp.c b/library/ecp.c
index 758d54b..66b3dc1 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -3305,7 +3305,7 @@
 int mbedtls_ecp_write_key(mbedtls_ecp_keypair *key,
                           unsigned char *buf, size_t buflen)
 {
-    int ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
 #if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED)
     if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_MONTGOMERY) {