diff --git a/library/pkwrite.c b/library/pkwrite.c
index 15b8a8d..c7eb114 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -527,7 +527,7 @@
         } else if (PSA_KEY_TYPE_IS_RSA(opaque_key_type)) {
             return MBEDTLS_PK_RSA;
         } else {
-            return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
+            return MBEDTLS_PK_NONE;
         }
     } else
 #endif