diff --git a/library/pk.c b/library/pk.c
index 2516eed..04c5e40 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -908,6 +908,8 @@
             return PSA_PK_TO_MBEDTLS_ERR(status);
         }
 
+        mbedtls_platform_zeroize(d, sizeof(d));
+
         /* make PK context wrap the key slot */
         mbedtls_pk_free(pk);
         mbedtls_pk_init(pk);