diff --git a/src/librustc/infer/region_constraints/mod.rs b/src/librustc/infer/region_constraints/mod.rs
index 2c580e2e349..8379a73bb9e 100644
--- a/src/librustc/infer/region_constraints/mod.rs
+++ b/src/librustc/infer/region_constraints/mod.rs
@@ -339,8 +339,6 @@ impl TaintDirections {
     }
 }
 
-pub struct ConstraintInfo {}
-
 impl<'tcx> RegionConstraintCollector<'tcx> {
     pub fn new() -> Self {
         Self::default()
diff --git a/src/librustc_driver/lib.rs b/src/librustc_driver/lib.rs
index 2e6dde6459a..f68ea7e0770 100644
--- a/src/librustc_driver/lib.rs
+++ b/src/librustc_driver/lib.rs
@@ -120,10 +120,6 @@ pub trait Callbacks {
     }
 }
 
-pub struct DefaultCallbacks;
-
-impl Callbacks for DefaultCallbacks {}
-
 #[derive(Default)]
 pub struct TimePassesCallbacks {
     time_passes: bool,