diff --git a/examples/rtic_bare6.rs b/examples/rtic_bare6.rs
index f3b965fcacf47236d5a5b8652802f1f64ee8b7ab..4ba4e82d4a740990cd0e45762094b097085f11eb 100644
--- a/examples/rtic_bare6.rs
+++ b/examples/rtic_bare6.rs
@@ -256,7 +256,7 @@ fn clock_out(rcc: &RCC, gpioc: &GPIOC) {
 //
 //    Compute the value of SYSCLK based on the oscilloscope reading
 //
-//    about 4MHz
+//    about 4MHz on PC9 which corresponds to 16MHz on sysclk.
 //
 //    What is the peak to peak (voltage) reading of the signal?
 //