diff --git a/src/bin/miri.rs b/src/bin/miri.rs
index 644a8129eee..7d32ee42573 100644
--- a/src/bin/miri.rs
+++ b/src/bin/miri.rs
@@ -7,7 +7,6 @@
 
 extern crate rustc_data_structures;
 extern crate rustc_driver;
-extern crate rustc_errors;
 extern crate rustc_hir;
 extern crate rustc_interface;
 extern crate rustc_metadata;
diff --git a/src/concurrency/sync.rs b/src/concurrency/sync.rs
index d301ced8511..464f452ca76 100644
--- a/src/concurrency/sync.rs
+++ b/src/concurrency/sync.rs
@@ -44,7 +44,7 @@ macro_rules! declare_id {
         }
 
         impl $name {
-            pub fn to_u32_scalar<'tcx>(&self) -> Scalar<Provenance> {
+            pub fn to_u32_scalar(&self) -> Scalar<Provenance> {
                 Scalar::from_u32(self.0.get())
             }
         }
diff --git a/src/shims/unix/fs.rs b/src/shims/unix/fs.rs
index edeb2001f93..8464c4589ed 100644
--- a/src/shims/unix/fs.rs
+++ b/src/shims/unix/fs.rs
@@ -246,7 +246,7 @@ impl FileDescriptor for DummyOutput {
         Ok(Ok(bytes.len()))
     }
 
-    fn dup<'tcx>(&mut self) -> io::Result<Box<dyn FileDescriptor>> {
+    fn dup(&mut self) -> io::Result<Box<dyn FileDescriptor>> {
         Ok(Box::new(DummyOutput))
     }
 }