diff --git a/src/ccid/ccid2040.c b/src/ccid/ccid2040.c
index 3ffe1e6..3da4212 100644
--- a/src/ccid/ccid2040.c
+++ b/src/ccid/ccid2040.c
@@ -340,6 +340,8 @@ int process_apdu() {
 
 uint16_t set_res_sw(uint8_t sw1, uint8_t sw2) {
     apdu.sw = (sw1 << 8) | sw2;
+    if (sw1 != 0x90 || sw2 != 0x00)
+        res_APDU_size = 0;
     return make_uint16_t(sw1, sw2);
 }