diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index c2c2b6f..dd39e81 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2243,6 +2243,7 @@
         mbedtls_zeroize_and_free(ssl->handshake->psk,
                                  ssl->handshake->psk_len);
         ssl->handshake->psk_len = 0;
+        ssl->handshake->psk = NULL;
     }
 #endif /* MBEDTLS_USE_PSA_CRYPTO */
 }