diff --git a/tests/timer/clk_override_test.c b/tests/timer/clk_override_test.c
new file mode 100644
index 0000000..308e821
--- /dev/null
+++ b/tests/timer/clk_override_test.c
@@ -0,0 +1,89 @@
+/*
+ * (C) 2008 by Holger Hans Peter Freyther <zecke@selfish.org>
+ * (C) 2011 by Harald Welte <laforge@gnumonks.org>
+ * All Rights Reserved
+ *
+ * Authors: Holger Hans Peter Freyther <zecke@selfish.org>
+ *	    Pablo Neira Ayuso <pablo@gnumonks.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/timer_compat.h>
+
+int main(int argc, char *argv[])
+{
+
+	struct timespec ts1 = { 123, 456 }, ts2 = {1, 200};
+	struct timespec read1, read2, res;
+	struct timespec *mono;
+
+	osmo_clock_gettime(CLOCK_BOOTTIME, &read1);
+	usleep(500);
+	osmo_clock_gettime(CLOCK_BOOTTIME, &read2);
+	if (!timespeccmp(&read2, &read1, >))
+		return EXIT_FAILURE;
+	printf("Non implemented clocks work fine\n");
+
+	osmo_clock_gettime(CLOCK_MONOTONIC, &read1);
+	usleep(500);
+	osmo_clock_gettime(CLOCK_MONOTONIC, &read2);
+	if (!timespeccmp(&read2, &read1, >))
+		return EXIT_FAILURE;
+	printf("Monotonic clock is working fine by default\n");
+
+	osmo_clock_override_enable(CLOCK_MONOTONIC, true);
+	printf("Monotonic clock override enabled\n");
+
+	mono = osmo_clock_override_gettimespec(CLOCK_MONOTONIC);
+	if (timespecisset(mono))
+		return EXIT_FAILURE;
+	printf("Monotonic override is cleared by default\n");
+
+	memcpy(mono, &ts1, sizeof(struct timespec));
+	osmo_clock_gettime(CLOCK_MONOTONIC, &read1);
+	if (!timespeccmp(&ts1, &read1, ==))
+		return EXIT_FAILURE;
+	printf("Monotonic clock can be overriden\n");
+
+	osmo_clock_override_add(CLOCK_MONOTONIC, ts2.tv_sec, ts2.tv_nsec);
+	osmo_clock_gettime(CLOCK_MONOTONIC, &read1);
+	timespecadd(&ts2, &ts1, &res);
+	if (!timespeccmp(&res, &read1, ==))
+		return EXIT_FAILURE;
+	printf("osmo_clock_override_add works fine.\n");
+
+	osmo_clock_override_enable(CLOCK_MONOTONIC, false);
+	printf("Monotonic clock override disabled\n");
+
+	osmo_clock_gettime(CLOCK_MONOTONIC, &read1);
+	usleep(500);
+	osmo_clock_gettime(CLOCK_MONOTONIC, &read2);
+	if (!timespeccmp(&read2, &read1, >))
+		return EXIT_FAILURE;
+	printf("Monotonic clock is working fine after enable+disable.\n");
+
+	return 0;
+}
diff --git a/tests/timer/clk_override_test.ok b/tests/timer/clk_override_test.ok
new file mode 100644
index 0000000..1fb519c
--- /dev/null
+++ b/tests/timer/clk_override_test.ok
@@ -0,0 +1,8 @@
+Non implemented clocks work fine
+Monotonic clock is working fine by default
+Monotonic clock override enabled
+Monotonic override is cleared by default
+Monotonic clock can be overriden
+osmo_clock_override_add works fine.
+Monotonic clock override disabled
+Monotonic clock is working fine after enable+disable.