diff --git a/src/Clock.cpp b/src/Clock.cpp
index 2c80205..4901852 100644
--- a/src/Clock.cpp
+++ b/src/Clock.cpp
@@ -6,17 +6,44 @@
 #include "Clock.h"
 #include "mbed.h"
 
-void clock_setup(void) {
-	// mbed reads the RTC at boot, do nothing for now
-}
+typedef std::chrono::time_point<Kernel::Clock> kernel_timepoint;
+typedef std::chrono::duration<Kernel::Clock> kernel_duration;
 
-struct timeval clock_time() {
+Mutex clock_lock;
+kernel_timepoint clock_timepoint;
+struct timeval clock_timeval;
+
+struct timeval get_rtc_time() {
 	struct timeval timeval;
 	timeval.tv_sec = time(NULL);
 	timeval.tv_usec = 0;
 	return timeval;
 }
 
+void clock_setup(void) {
+	clock_lock.lock();
+	clock_timeval = get_rtc_time();
+	clock_timepoint = Kernel::Clock::now();
+	clock_lock.unlock();
+}
+
+struct timeval clock_time() {
+	clock_lock.lock();
+	kernel_timepoint now = Kernel::Clock::now();
+	std::chrono::microseconds elapsed = now - clock_timepoint;
+	clock_lock.unlock();
+
+	uint64_t microsecs = 0;
+	microsecs += clock_timeval.tv_usec;
+	microsecs += clock_timeval.tv_sec * 1000000;
+	microsecs += elapsed.count();
+
+	struct timeval time;
+	time.tv_sec = microsecs / 1000000;
+	time.tv_usec = microsecs % 1000000;
+	return time;
+}
+
 SNTPError clock_sync(NetworkInterface &net) {
 	struct timeval time;
 	SNTPError err;
@@ -24,6 +51,10 @@
 	if (err != SNTPSuccess) {
 		return err;
 	}
+	clock_lock.lock();
+	clock_timeval = time;
+	clock_timepoint = Kernel::Clock::now();
+	clock_lock.unlock();
 	set_time(time.tv_sec);
 	return SNTPSuccess;
 }