diff --git a/src/interrupt.rs b/src/interrupt.rs
index 06b91f17..72450c4b 100644
--- a/src/interrupt.rs
+++ b/src/interrupt.rs
@@ -77,3 +77,15 @@ where
 
     r
 }
+
+// Make a `free()` function available to allow checking dependencies without specifying a target,
+// but that will panic at runtime if executed.
+#[doc(hidden)]
+#[cfg(not(cortex_m))]
+#[inline]
+pub fn free<F, R>(_: F) -> R
+where
+    F: FnOnce(&CriticalSection) -> R,
+{
+    panic!("cortex_m::interrupt::free() is only functional on cortex-m platforms");
+}
diff --git a/src/peripheral/tpiu.rs b/src/peripheral/tpiu.rs
index 07624951..14dd35ca 100644
--- a/src/peripheral/tpiu.rs
+++ b/src/peripheral/tpiu.rs
@@ -118,7 +118,6 @@ impl TPIU {
     /// [`trace_output_protocol`](Self::set_trace_output_protocol).
     #[inline]
     pub fn trace_output_protocol(&self) -> Option<TraceProtocol> {
-        use core::convert::TryInto;
         self.sppr.read().txmode().try_into().ok()
     }