1 files changed, 2 insertions, 2 deletions
diff --git a/compiler/rustc_middle/src/mir/switch_sources.rs b/compiler/rustc_middle/src/mir/switch_sources.rs
index adeeec70d1c..fbb26800e29 100644
--- a/compiler/rustc_middle/src/mir/switch_sources.rs
+++ b/compiler/rustc_middle/src/mir/switch_sources.rs
@@ -56,8 +56,8 @@ impl SwitchSourceCache {
 
 impl<S: serialize::Encoder> serialize::Encodable<S> for SwitchSourceCache {
     #[inline]
-    fn encode(&self, s: &mut S) -> Result<(), S::Error> {
-        s.emit_unit()
+    fn encode(&self, _s: &mut S) -> Result<(), S::Error> {
+        Ok(())
     }
 }