diff --git a/shared/timespec-util.h b/shared/timespec-util.h
index a1d6881..13948b1 100644
--- a/shared/timespec-util.h
+++ b/shared/timespec-util.h
@@ -70,6 +70,18 @@
 	}
 }
 
+/* Add a millisecond value to a timespec
+ *
+ * \param r[out] result: a + b
+ * \param a[in] base operand as timespec
+ * \param b[in] operand in milliseconds
+ */
+static inline void
+timespec_add_msec(struct timespec *r, const struct timespec *a, int64_t b)
+{
+	return timespec_add_nsec(r, a, b * 1000000);
+}
+
 /* Convert timespec to nanoseconds
  *
  * \param a timespec
diff --git a/tests/timespec-test.c b/tests/timespec-test.c
index 91d53f7..cd3b1c1 100644
--- a/tests/timespec-test.c
+++ b/tests/timespec-test.c
@@ -122,3 +122,14 @@
 	ZUC_ASSERT_EQ(16, r.tv_sec);
 	ZUC_ASSERT_EQ(0, r.tv_nsec);
 }
+
+ZUC_TEST(timespec_test, timespec_add_msec)
+{
+	struct timespec a, r;
+
+	a.tv_sec = 1000;
+	a.tv_nsec = 1;
+	timespec_add_msec(&r, &a, 2002);
+	ZUC_ASSERT_EQ(1002, r.tv_sec);
+	ZUC_ASSERT_EQ(2000001, r.tv_nsec);
+}