diff --git a/src/eapol.c b/src/eapol.c
index 7fc19b3e..c347e4a9 100644
--- a/src/eapol.c
+++ b/src/eapol.c
@@ -1127,7 +1127,7 @@ static void eapol_handle_ptk_3_of_4(struct eapol_sm *sm,
 			return;
 		}
 
-		igtk_key_index = util_bit_field(igtk[0], 0, 2);
+		igtk_key_index = l_get_le16(igtk);;
 		igtk += 2;
 		igtk_len -= 2;
 	} else