diff --git a/apps/sel4test-driver/src/timer.h b/apps/sel4test-driver/src/timer.h
index 5fd0d9bf..100271af 100644
--- a/apps/sel4test-driver/src/timer.h
+++ b/apps/sel4test-driver/src/timer.h
@@ -11,7 +11,7 @@
 
 #define TIMER_ID 0
 
-/* Timing related functions used only by in sel4test-driver */
+/* Timing related functions used only within sel4test-driver */
 void handle_timer_interrupts(driver_env_t env, seL4_Word badge);
 void wait_for_timer_interrupt(driver_env_t env);
 void timeout(driver_env_t env, uint64_t ns, timeout_type_t timeout);