diff --git a/docs/Code_Overview.md b/docs/Code_Overview.md
index 207b37f4..ee640457 100644
--- a/docs/Code_Overview.md
+++ b/docs/Code_Overview.md
@@ -54,7 +54,7 @@ functions should never pause, delay, or do any work that lasts more
 than a few micro-seconds. These functions schedule work at specific
 times by scheduling timers.
 
-Timer functions are scheduled by calling sched_timer() (located in
+Timer functions are scheduled by calling sched_add_timer() (located in
 **src/sched.c**). The scheduler code will arrange for the given
 function to be called at the requested clock time. Timer interrupts
 are initially handled in an architecture specific interrupt handler
diff --git a/src/adccmds.c b/src/adccmds.c
index 81a7fff5..5f1fabb4 100644
--- a/src/adccmds.c
+++ b/src/adccmds.c
@@ -74,7 +74,7 @@ command_query_analog_in(uint32_t *args)
     a->max_value = args[6];
     if (! a->sample_count)
         return;
-    sched_timer(&a->timer);
+    sched_add_timer(&a->timer);
 }
 DECL_COMMAND(command_query_analog_in,
              "query_analog_in oid=%c clock=%u sample_ticks=%u sample_count=%c"
diff --git a/src/basecmd.c b/src/basecmd.c
index 2170415a..8049e376 100644
--- a/src/basecmd.c
+++ b/src/basecmd.c
@@ -209,7 +209,7 @@ command_start_group(uint32_t *args)
     sched_del_timer(&group_timer);
     group_timer.func = group_end_event;
     group_timer.waketime = args[0];
-    sched_timer(&group_timer);
+    sched_add_timer(&group_timer);
 }
 DECL_COMMAND(command_start_group, "start_group clock=%u");
 
diff --git a/src/endstop.c b/src/endstop.c
index 913bb466..a504de92 100644
--- a/src/endstop.c
+++ b/src/endstop.c
@@ -64,7 +64,7 @@ command_end_stop_home(uint32_t *args)
         return;
     }
     e->flags = ESF_HOMING | (args[3] ? ESF_PIN_HIGH : 0);
-    sched_timer(&e->time);
+    sched_add_timer(&e->time);
 }
 DECL_COMMAND(command_end_stop_home,
              "end_stop_home oid=%c clock=%u rest_ticks=%u pin_value=%c");
diff --git a/src/gpiocmds.c b/src/gpiocmds.c
index 259a7a5f..e3351b44 100644
--- a/src/gpiocmds.c
+++ b/src/gpiocmds.c
@@ -8,7 +8,7 @@
 #include "board/gpio.h" // struct gpio_out
 #include "board/irq.h" // irq_disable
 #include "command.h" // DECL_COMMAND
-#include "sched.h" // sched_timer
+#include "sched.h" // sched_add_timer
 
 
 /****************************************************************
@@ -61,7 +61,7 @@ command_schedule_digital_out(uint32_t *args)
     d->timer.func = digital_out_event;
     d->timer.waketime = args[1];
     d->value = args[2];
-    sched_timer(&d->timer);
+    sched_add_timer(&d->timer);
 }
 DECL_COMMAND(command_schedule_digital_out,
              "schedule_digital_out oid=%c clock=%u value=%c");
@@ -202,7 +202,7 @@ command_schedule_soft_pwm_out(uint32_t *args)
         sched_del_timer(&s->timer);
         s->timer.waketime = time;
         s->timer.func = soft_pwm_load_event;
-        sched_timer(&s->timer);
+        sched_add_timer(&s->timer);
     }
     irq_enable();
 }
diff --git a/src/pwmcmds.c b/src/pwmcmds.c
index 2865b62a..e8de0a3b 100644
--- a/src/pwmcmds.c
+++ b/src/pwmcmds.c
@@ -7,7 +7,7 @@
 #include "basecmd.h" // oid_alloc
 #include "board/gpio.h" // struct gpio_pwm
 #include "command.h" // DECL_COMMAND
-#include "sched.h" // sched_timer
+#include "sched.h" // sched_add_timer
 
 struct pwm_out_s {
     struct timer timer;
@@ -54,7 +54,7 @@ command_schedule_pwm_out(uint32_t *args)
     p->timer.func = pwm_event;
     p->timer.waketime = args[1];
     p->value = args[2];
-    sched_timer(&p->timer);
+    sched_add_timer(&p->timer);
 }
 DECL_COMMAND(command_schedule_pwm_out,
              "schedule_pwm_out oid=%c clock=%u value=%c");
diff --git a/src/sched.c b/src/sched.c
index 6ccf8e5a..83c02075 100644
--- a/src/sched.c
+++ b/src/sched.c
@@ -97,7 +97,7 @@ static struct timer *timer_list = &ms_timer;
 
 // Schedule a function call at a supplied time.
 void
-sched_timer(struct timer *add)
+sched_add_timer(struct timer *add)
 {
     uint32_t waketime = add->waketime;
     irqstatus_t flag = irq_save();
diff --git a/src/sched.h b/src/sched.h
index 9685317f..0c1820c3 100644
--- a/src/sched.h
+++ b/src/sched.h
@@ -12,7 +12,7 @@
 // Declare a shutdown function (called on an emergency stop)
 #define DECL_SHUTDOWN(FUNC) _DECL_CALLBACK(shutdownfuncs, FUNC)
 
-// Timer structure for scheduling timed events (see sched_timer() )
+// Timer structure for scheduling timed events (see sched_add_timer() )
 struct timer {
     struct timer *next;
     uint_fast8_t (*func)(struct timer*);
@@ -26,7 +26,7 @@ uint8_t sched_check_periodic(uint16_t time, uint16_t *pnext);
 uint32_t sched_from_us(uint32_t us);
 uint32_t sched_read_time(void);
 uint8_t sched_is_before(uint32_t time1, uint32_t time2);
-void sched_timer(struct timer*);
+void sched_add_timer(struct timer*);
 void sched_del_timer(struct timer *del);
 void sched_timer_kick(void);
 uint8_t sched_is_shutdown(void);
diff --git a/src/stepper.c b/src/stepper.c
index b196dc61..0d7f490b 100644
--- a/src/stepper.c
+++ b/src/stepper.c
@@ -202,7 +202,7 @@ command_queue_step(uint32_t *args)
     } else {
         s->first = m;
         stepper_load_next(s, s->next_step_time + m->interval);
-        sched_timer(&s->time);
+        sched_add_timer(&s->time);
     }
     irq_enable();
 }