diff --git a/modb_orno3.c b/modb_orno3.c
index 5e6bba0..47f105a 100644
--- a/modb_orno3.c
+++ b/modb_orno3.c
@@ -535,6 +535,7 @@ int main(int argc, char *argv[])
     int voltage_buffer_index = 0;
     int voltage_buffer_items = 0;
     time_t high_frequency_mode_end_time = 0;
+    int high_frequency_mode_active = 0;  /* Flag to track if we notified about high freq mode */
 
     time_t rawtime;
     struct tm *timeinfo;
@@ -674,8 +675,9 @@ int main(int argc, char *argv[])
                 fabs(current_voltage.U3 - avg_L3) > avg_L3 * VOLTAGE_FLUCTUATION_THRESHOLD) {
                 printf("ORNO: Voltage fluctuation detected! Switching to high frequency polling for %d seconds.\n", HIGH_FREQ_MODE_DURATION);
                 mqtt_send("/energy/orno/fluct", "on");
-                influx_send_post("orno,device=orno,highfluct=start highfluct=true");
+                influx_send_post("orno,device=orno,highfluct=start highfluct=1");
                 high_frequency_mode_end_time = time(NULL) + HIGH_FREQ_MODE_DURATION;
+                high_frequency_mode_active = 1;
             }
 
 
@@ -1050,6 +1052,13 @@ int main(int argc, char *argv[])
             if (time(NULL) < high_frequency_mode_end_time) {
                 usleep(10000); // 10ms
             } else {
+                // Check if high frequency mode just ended - send notification
+                if (high_frequency_mode_active) {
+                    printf("ORNO: High frequency mode ended after %d seconds.\n", HIGH_FREQ_MODE_DURATION);
+                    mqtt_send("/energy/orno/fluct", "off");
+                    influx_send_post("orno,device=orno,highfluct=end highfluct=0");
+                    high_frequency_mode_active = 0;
+                }
                 sleep(5); // 5s
             }
         }