diff --git a/compiler/rustc_mir/src/transform/simplify.rs b/compiler/rustc_mir/src/transform/simplify.rs
index b7c9a3a8688ec..289231e52cb41 100644
--- a/compiler/rustc_mir/src/transform/simplify.rs
+++ b/compiler/rustc_mir/src/transform/simplify.rs
@@ -61,7 +61,7 @@ impl<'tcx> MirPass<'tcx> for SimplifyCfg {
     }
 
     fn run_pass(&self, _tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
-        debug!("SimplifyCfg({:?}) - simplifying {:?}", self.label, body);
+        debug!("SimplifyCfg({:?}) - simplifying {:?}", self.label, body.source);
         simplify_cfg(body);
     }
 }