diff --git a/src/libopensc/card-iasecc.c b/src/libopensc/card-iasecc.c
index 9fa53b22..38ccc75b 100644
--- a/src/libopensc/card-iasecc.c
+++ b/src/libopensc/card-iasecc.c
@@ -421,7 +421,9 @@ static int iasecc_parse_ef_atr(struct sc_card *card)
 	sizes->recv =	 card->ef_atr->issuer_data[10] * 0x100 + card->ef_atr->issuer_data[11];
 	sizes->recv_sc = card->ef_atr->issuer_data[14] * 0x100 + card->ef_atr->issuer_data[15];
 
-	sc_log(ctx, "EF.ATR: IO Buffer Size send/sc %ld/%ld recv/sc %ld/%ld",
+	sc_log(ctx,
+		"EF.ATR: IO Buffer Size send/sc %"SC_FORMAT_LEN_SIZE_T"d/%"SC_FORMAT_LEN_SIZE_T"d "
+		"recv/sc %"SC_FORMAT_LEN_SIZE_T"d/%"SC_FORMAT_LEN_SIZE_T"d",
 		sizes->send, sizes->send_sc, sizes->recv, sizes->recv_sc);
 
 	card->max_send_size = sizes->send;