diff --git a/src/lmic/lmic_bandplan_as923.h b/src/lmic/lmic_bandplan_as923.h
index 845541af..206d4a7d 100644
--- a/src/lmic/lmic_bandplan_as923.h
+++ b/src/lmic/lmic_bandplan_as923.h
@@ -72,7 +72,7 @@ void LMICas923_init(void);
 
 // override default for LMICbandplan_isFSK()
 #undef LMICbandplan_isFSK
-#define LMICbandplan_isFSK()    (/* TX datarate */LMIC.rxsyms == AS923_DR_FSK)
+#define LMICbandplan_isFSK()    (/* RX datarate */LMIC.dndr == AS923_DR_FSK)
 
 // txDone handling for FSK.
 void
diff --git a/src/lmic/lmic_bandplan_eu868.h b/src/lmic/lmic_bandplan_eu868.h
index 4952d3e4..13417ecd 100644
--- a/src/lmic/lmic_bandplan_eu868.h
+++ b/src/lmic/lmic_bandplan_eu868.h
@@ -59,7 +59,7 @@ LMICeu868_isValidBeacon1(const uint8_t *d) {
 
 // override default for LMICbandplan_isFSK()
 #undef LMICbandplan_isFSK
-#define LMICbandplan_isFSK()    (/* TX datarate */LMIC.rxsyms == EU868_DR_FSK)
+#define LMICbandplan_isFSK()    (/* RX datarate */LMIC.dndr == EU868_DR_FSK)
 
 // txDone handling for FSK.
 void
diff --git a/src/lmic/lmic_bandplan_in866.h b/src/lmic/lmic_bandplan_in866.h
index 39b58f15..9fc08264 100644
--- a/src/lmic/lmic_bandplan_in866.h
+++ b/src/lmic/lmic_bandplan_in866.h
@@ -56,7 +56,7 @@ LMICin866_isValidBeacon1(const uint8_t *d) {
 
 // override default for LMICbandplan_isFSK()
 #undef LMICbandplan_isFSK
-#define LMICbandplan_isFSK()    (/* TX datarate */LMIC.rxsyms == IN866_DR_FSK)
+#define LMICbandplan_isFSK()    (/* TX datarate */LMIC.dndr == IN866_DR_FSK)
 
 // txDone handling for FSK.
 void
diff --git a/src/lmic/lmic_eu868.c b/src/lmic/lmic_eu868.c
index b91e1ea8..d4b9b6b3 100644
--- a/src/lmic/lmic_eu868.c
+++ b/src/lmic/lmic_eu868.c
@@ -247,7 +247,7 @@ ostime_t LMICeu868_nextJoinState(void) {
 }
 #endif // !DISABLE_JOIN
 
-// txDone handling for FSK.
+// Class A txDone handling for FSK.
 void
 LMICeu868_txDoneFSK(ostime_t delay, osjobcb_t func) {
         LMIC.rxtime = LMIC.txend + delay - PRERX_FSK*us2osticksRound(160);
diff --git a/src/lmic/lmic_in866.c b/src/lmic/lmic_in866.c
index 86571bc0..78c5e81a 100644
--- a/src/lmic/lmic_in866.c
+++ b/src/lmic/lmic_in866.c
@@ -212,7 +212,7 @@ ostime_t LMICin866_nextJoinState(void) {
 }
 #endif // !DISABLE_JOIN
 
-// txDone handling for FSK.
+// Class A txDone handling for FSK.
 void
 LMICin866_txDoneFSK(ostime_t delay, osjobcb_t func) {
         LMIC.rxtime = LMIC.txend + delay - PRERX_FSK*us2osticksRound(160);