diff --git a/src/PN532.cpp b/src/PN532.cpp
index f4df823..c9d16d7 100644
--- a/src/PN532.cpp
+++ b/src/PN532.cpp
@@ -242,6 +242,9 @@ bool PN532::readPassiveTargetID(uint8_t cardbaudrate, uint8_t *uid, uint8_t *uid
   if (pn532_packetbuffer[0] != 1)
     return 0;
 
+  if (pn532_packetbuffer[4] != 0x08) // SAK == 0x08
+    return 0;
+
   uint16_t sens_res = pn532_packetbuffer[2];
   sens_res <<= 8;
   sens_res |= pn532_packetbuffer[3];