diff --git a/ampel-firmware/ampel-firmware.h b/ampel-firmware/ampel-firmware.h
index b6a3d013b85a84851122c493d8d8172a93985d0c..abe783aea97c4aa368cd0eb940dda401b131375a 100644
--- a/ampel-firmware/ampel-firmware.h
+++ b/ampel-firmware/ampel-firmware.h
@@ -33,7 +33,7 @@
 #endif
 
 #include "util.h"
-#include "time_util.h"
+#include "ntp.h"
 #include "sensor_console.h"
 #include "co2_sensor.h"
 #include "led_effects.h"
diff --git a/ampel-firmware/co2_sensor.cpp b/ampel-firmware/co2_sensor.cpp
index fe02da678d0e77b83aa7e6f4cfce3a56dbad8c04..fae9895334099e885b8820b26eeb142e531364dc 100644
--- a/ampel-firmware/co2_sensor.cpp
+++ b/ampel-firmware/co2_sensor.cpp
@@ -1,7 +1,7 @@
 #include "co2_sensor.h"
 
 #include "config.h"
-#include "time_util.h"
+#include "ntp.h"
 #include "led_effects.h"
 #include "sensor_console.h"
 #include <Wire.h>
diff --git a/ampel-firmware/csv_writer.cpp b/ampel-firmware/csv_writer.cpp
index ec59f3cf8cea29a59faba803c3dd1c35dc20bade..35972cde0447c34b6ff32a14a4627b684730b3b5 100644
--- a/ampel-firmware/csv_writer.cpp
+++ b/ampel-firmware/csv_writer.cpp
@@ -1,7 +1,7 @@
 #include "csv_writer.h"
 
 #include "config.h"
-#include "time_util.h"
+#include "ntp.h"
 #include "led_effects.h"
 #include "sensor_console.h"
 
diff --git a/ampel-firmware/lorawan.cpp b/ampel-firmware/lorawan.cpp
index 6f849d47b7dcf3129c8ce9a0d137ca9cdc9b88b5..5dfad5e5c1fadb1df3018bc142e438ef7a55a9a9 100644
--- a/ampel-firmware/lorawan.cpp
+++ b/ampel-firmware/lorawan.cpp
@@ -5,7 +5,7 @@
 #include "led_effects.h"
 #include "sensor_console.h"
 #include "util.h"
-#include "time_util.h"
+#include "ntp.h"
 
 /*** Define region and transceiver type, and ignore lmic_project_config.h from lmic library ***/
 // Those values are probably okay if you're in Europe.
diff --git a/ampel-firmware/mqtt.cpp b/ampel-firmware/mqtt.cpp
index d393e710b5484fc6baed93e5a34bd295dab3968a..57b5cd026f57586339e3d90eeb91aa204c242300 100644
--- a/ampel-firmware/mqtt.cpp
+++ b/ampel-firmware/mqtt.cpp
@@ -4,7 +4,7 @@
 #include "led_effects.h"
 #include "sensor_console.h"
 #include "wifi_util.h"
-#include "time_util.h"
+#include "ntp.h"
 #include "src/lib/PubSubClient/src/PubSubClient.h"
 
 #if defined(ESP8266)
diff --git a/ampel-firmware/time_util.cpp b/ampel-firmware/ntp.cpp
similarity index 98%
rename from ampel-firmware/time_util.cpp
rename to ampel-firmware/ntp.cpp
index b37fcaf0a70f7cd2aac17e10287267c5db2a78d7..79d429f6c21f15e8ed47e1323c3350c6f54d7cff 100644
--- a/ampel-firmware/time_util.cpp
+++ b/ampel-firmware/ntp.cpp
@@ -1,4 +1,4 @@
-#include "time_util.h"
+#include "ntp.h"
 #include "sensor_console.h"
 #include "config.h"
 #include <WiFiUdp.h> // required for NTP
diff --git a/ampel-firmware/time_util.h b/ampel-firmware/ntp.h
similarity index 100%
rename from ampel-firmware/time_util.h
rename to ampel-firmware/ntp.h
diff --git a/ampel-firmware/web_server.cpp b/ampel-firmware/web_server.cpp
index 86ebb19c07aca75d24f28012a6b471b79ce85734..266be7cfa7f33eeb42510182bedd87819a3a70d3 100644
--- a/ampel-firmware/web_server.cpp
+++ b/ampel-firmware/web_server.cpp
@@ -8,7 +8,7 @@
 
 #include "config.h"
 #include "util.h"
-#include "time_util.h"
+#include "ntp.h"
 #include "wifi_util.h"
 #include "co2_sensor.h"
 #include "sensor_console.h"
diff --git a/ampel-firmware/wifi_util.cpp b/ampel-firmware/wifi_util.cpp
index 7200206b2c2e530f24652112c7aec8bd5161ffc9..131a61574bdcec7d83c7087474cf44b87f34147f 100644
--- a/ampel-firmware/wifi_util.cpp
+++ b/ampel-firmware/wifi_util.cpp
@@ -2,7 +2,7 @@
 
 #include "config.h"
 #include "util.h"
-#include "time_util.h"
+#include "ntp.h"
 #include "led_effects.h"
 #include "sensor_console.h"