diff --git a/src/lmic_config.h b/src/lmic_config.h
index d7759a03..d8a88c7a 100644
--- a/src/lmic_config.h
+++ b/src/lmic_config.h
@@ -21,7 +21,7 @@
 #define LMIC_USE_INTERRUPTS 1
 
 // time sync via LoRaWAN network, note: not supported by TTNv2
-//#define LMIC_ENABLE_DeviceTimeReq 1
+#define LMIC_ENABLE_DeviceTimeReq 1
 
 // use callback event handlers, not onEvent() reference
 #define LMIC_ENABLE_onEvent 0
diff --git a/src/paxcounter.conf b/src/paxcounter.conf
index ac392f24..3cc7f2e3 100644
--- a/src/paxcounter.conf
+++ b/src/paxcounter.conf
@@ -72,15 +72,15 @@
 #define OTA_MIN_BATT                    3600    // minimum battery level for OTA [millivolt]
 #define RESPONSE_TIMEOUT_MS             60000   // firmware binary server connection timeout [milliseconds]
 
-// settings for syncing time of node with external time source
+// settings for syncing time of node with a time source (network / gps / rtc / timeserver)
+#define TIME_SYNC_LORAWAN               1       // set to 1 to use LORA network as time source, 0 means off [default = 1]
 #define TIME_SYNC_INTERVAL              60      // sync time attempt each .. minutes from time source (GPS/LORA/RTC) [default = 60], 0 means off
 #define TIME_SYNC_INTERVAL_RETRY        10      // retry time sync after lost sync each .. minutes [default = 10], 0 means off
 #define TIME_SYNC_COMPILEDATE           0       // set to 1 to use compile date to initialize RTC after power outage [default = 0]
-#define TIME_SYNC_LORAWAN               0       // set to 1 to use LORA network as time source, 0 means off [default = 0]
-#define TIME_SYNC_LORASERVER            0       // set to 1 to use LORA timeserver as time source, 0 means off [default = 0]
 
-// settings for syncing time with timeserver applications
-#define TIME_SYNC_SAMPLES               1       // number of time requests for averaging
+// specific settings for syncing time of node with a timeserver
+#define TIME_SYNC_LORASERVER            0       // set to 1 to use LORA timeserver as time source, 0 means off [default = 0]
+#define TIME_SYNC_SAMPLES               1       // number of time requests for averaging, max. 255
 #define TIME_SYNC_CYCLE                 60      // delay between two time samples [seconds]
 #define TIME_SYNC_TIMEOUT               300     // timeout waiting for timeserver answer [seconds]