diff --git a/apis/adc/src/lib.rs b/apis/adc/src/lib.rs
index d2dc86ac..815cdb90 100644
--- a/apis/adc/src/lib.rs
+++ b/apis/adc/src/lib.rs
@@ -15,6 +15,8 @@ impl<S: Syscalls> Adc<S> {
     // current ADC driver in the kernel returns the number of ADC channels
     // instead of just success. This will be fixed in a future release of Tock,
     // but for now we workaround this issue.
+    //
+    // https://github.com/tock/tock/issues/3375
     pub fn exists() -> Result<u32, ErrorCode> {
         S::command(DRIVER_NUM, EXISTS, 0, 0).to_result()
     }