diff --git a/src/lmic_config.h b/src/lmic_config.h
index 0f1f426b..06a4da4c 100644
--- a/src/lmic_config.h
+++ b/src/lmic_config.h
@@ -37,7 +37,7 @@
 // so consuming more power. You may sharpen (reduce) this value if you are
 // limited on battery.
 // ATTN: VALUES > 7 WILL CAUSE RECEPTION AND JOIN PROBLEMS WITH HIGH SF RATES
-#define CLOCK_ERROR_PROCENTAGE 7
+//#define CLOCK_ERROR_PROCENTAGE 7
 
 // Set this to 1 to enable some basic debug output (using printf) about
 // RF settings used during transmission and reception. Set to 2 to
diff --git a/src/lorawan.cpp b/src/lorawan.cpp
index 9ad8675a..1e8c641f 100644
--- a/src/lorawan.cpp
+++ b/src/lorawan.cpp
@@ -541,11 +541,13 @@ void lmictask(void *pvParameters) {
   os_init();    // initialize lmic run-time environment
   LMIC_reset(); // initialize lmic MAC
   LMIC_setLinkCheckMode(0);
-  // This tells LMIC to make the receive windows bigger, in case your clock is
-  // faster or slower. This causes the transceiver to be earlier switched on,
-  // so consuming more power. You may sharpen (reduce) CLOCK_ERROR_PERCENTAGE
-  // in src/lmic_config.h if you are limited on battery.
+// This tells LMIC to make the receive windows bigger, in case your clock is
+// faster or slower. This causes the transceiver to be earlier switched on,
+// so consuming more power. You may sharpen (reduce) CLOCK_ERROR_PERCENTAGE
+// in src/lmic_config.h if you are limited on battery.
+#ifdef CLOCK_ERROR_PROCENTAGE
   LMIC_setClockError(MAX_CLOCK_ERROR * CLOCK_ERROR_PROCENTAGE / 100);
+#endif
   // Set the data rate to Spreading Factor 7.  This is the fastest supported
   // rate for 125 kHz channels, and it minimizes air time and battery power.
   // Set the transmission power to 14 dBi (25 mW).