diff --git a/src/gps/RTC.cpp b/src/gps/RTC.cpp
index 4a629d755..4dd76e6c2 100644
--- a/src/gps/RTC.cpp
+++ b/src/gps/RTC.cpp
@@ -136,20 +136,35 @@ RTCSetResult perhapsSetRTC(RTCQuality q, const struct timeval *tv, bool forceUpd
     static uint32_t lastSetMsec = 0;
     uint32_t now = millis();
     uint32_t printableEpoch = tv->tv_sec; // Print lib only supports 32 bit but time_t can be 64 bit on some platforms
-#ifdef BUILD_EPOCH
+
+    // Debug the comparison before entering the block
+    uint64_t maxAllowedTime64_debug = (uint64_t)BUILD_EPOCH + FORTY_YEARS;
+    time_t maxAllowedTime_cast = (time_t)maxAllowedTime64_debug;
+    LOG_DEBUG("GPS comparison debug: tv_sec=%ld, maxAllowed64=%lu, maxAllowed_cast=%ld, sizeof(time_t)=%d", (long)tv->tv_sec,
+              (unsigned long)maxAllowedTime64_debug, (long)maxAllowedTime_cast, sizeof(time_t));
+
+#if defined(BUILD_EPOCH)
     if (tv->tv_sec < BUILD_EPOCH) {
         if (Throttle::isWithinTimespanMs(lastTimeValidationWarning, TIME_VALIDATION_WARNING_INTERVAL_MS) == false) {
             LOG_WARN("Ignore time (%ld) before build epoch (%ld)!", printableEpoch, BUILD_EPOCH);
             lastTimeValidationWarning = millis();
         }
         return RTCSetResultInvalidTime;
-    } else if (tv->tv_sec > (time_t)(BUILD_EPOCH + FORTY_YEARS)) {
+    } else if ((uint64_t)tv->tv_sec > ((uint64_t)BUILD_EPOCH + FORTY_YEARS)) {
         if (Throttle::isWithinTimespanMs(lastTimeValidationWarning, TIME_VALIDATION_WARNING_INTERVAL_MS) == false) {
             // Calculate max allowed time safely to avoid overflow in logging
-            uint64_t maxAllowedTime = (uint64_t)BUILD_EPOCH + FORTY_YEARS;
-            uint32_t maxAllowedPrintable = (maxAllowedTime > UINT32_MAX) ? UINT32_MAX : (uint32_t)maxAllowedTime;
-            LOG_WARN("Ignore time (%ld) too far in the future (build epoch: %ld, max allowed: %ld)!", printableEpoch,
-                     (uint32_t)BUILD_EPOCH, maxAllowedPrintable);
+            uint64_t maxAllowedTime64 = (uint64_t)BUILD_EPOCH + FORTY_YEARS;
+            LOG_DEBUG("GPS time validation: BUILD_EPOCH=%lu, maxAllowedTime64=%lu, UINT32_MAX=%lu", (unsigned long)BUILD_EPOCH,
+                      (unsigned long)maxAllowedTime64, (unsigned long)UINT32_MAX);
+
+            // For logging, show the actual 64-bit value or indicate overflow
+            if (maxAllowedTime64 <= UINT32_MAX) {
+                LOG_WARN("Ignore time (%ld) too far in the future (build epoch: %ld, max allowed: %ld)!", printableEpoch,
+                         (uint32_t)BUILD_EPOCH, (uint32_t)maxAllowedTime64);
+            } else {
+                LOG_WARN("Ignore time (%ld) too far in the future (build epoch: %ld, max allowed: >4294967295)!", printableEpoch,
+                         (uint32_t)BUILD_EPOCH);
+            }
             lastTimeValidationWarning = millis();
         }
         return RTCSetResultInvalidTime;
@@ -274,13 +289,21 @@ RTCSetResult perhapsSetRTC(RTCQuality q, struct tm &t)
             lastTimeValidationWarning = millis();
         }
         return RTCSetResultInvalidTime;
-    } else if (tv.tv_sec > (time_t)(BUILD_EPOCH + FORTY_YEARS)) {
+    } else if ((uint64_t)tv.tv_sec > ((uint64_t)BUILD_EPOCH + FORTY_YEARS)) {
         if (Throttle::isWithinTimespanMs(lastTimeValidationWarning, TIME_VALIDATION_WARNING_INTERVAL_MS) == false) {
             // Calculate max allowed time safely to avoid overflow in logging
-            uint64_t maxAllowedTime = (uint64_t)BUILD_EPOCH + FORTY_YEARS;
-            uint32_t maxAllowedPrintable = (maxAllowedTime > UINT32_MAX) ? UINT32_MAX : (uint32_t)maxAllowedTime;
-            LOG_WARN("Ignore time (%ld) too far in the future (build epoch: %ld, max allowed: %ld)!", printableEpoch,
-                     (uint32_t)BUILD_EPOCH, maxAllowedPrintable);
+            uint64_t maxAllowedTime64 = (uint64_t)BUILD_EPOCH + FORTY_YEARS;
+            LOG_DEBUG("GPS time validation: BUILD_EPOCH=%lu, maxAllowedTime64=%lu, UINT32_MAX=%lu", (unsigned long)BUILD_EPOCH,
+                      (unsigned long)maxAllowedTime64, (unsigned long)UINT32_MAX);
+
+            // For logging, show the actual 64-bit value or indicate overflow
+            if (maxAllowedTime64 <= UINT32_MAX) {
+                LOG_WARN("Ignore time (%ld) too far in the future (build epoch: %ld, max allowed: %ld)!", printableEpoch,
+                         (uint32_t)BUILD_EPOCH, (uint32_t)maxAllowedTime64);
+            } else {
+                LOG_WARN("Ignore time (%ld) too far in the future (build epoch: %ld, max allowed: >4294967295)!", printableEpoch,
+                         (uint32_t)BUILD_EPOCH);
+            }
             lastTimeValidationWarning = millis();
         }
         return RTCSetResultInvalidTime;
diff --git a/src/gps/RTC.h b/src/gps/RTC.h
index 1ecde79ae..eca17bf35 100644
--- a/src/gps/RTC.h
+++ b/src/gps/RTC.h
@@ -56,5 +56,5 @@ time_t gm_mktime(struct tm *tm);
 #define SEC_PER_HOUR 3600
 #define SEC_PER_MIN 60
 #ifdef BUILD_EPOCH
-#define FORTY_YEARS (40ULL * 365 * SEC_PER_DAY) // Use 64-bit arithmetic to prevent overflow
+static constexpr uint64_t FORTY_YEARS = (40ULL * 365 * SEC_PER_DAY); // Use 64-bit arithmetic to prevent overflow
 #endif