diff --git a/vm/src/api/mod.rs b/vm/src/api/mod.rs
index 0142ce3bfc..4938bb3fc3 100644
--- a/vm/src/api/mod.rs
+++ b/vm/src/api/mod.rs
@@ -536,8 +536,6 @@ pub trait Pushable<'vm>: AsyncPushable<'vm> {
     }
 }
 
-impl<T> Userdata for std::sync::RwLock<T> where T: Userdata {}
-
 /// Trait which allows rust values to be retrieved from the virtual machine
 pub trait Getable<'vm, 'value>: Sized {
     type Proxy: 'value;
diff --git a/vm/src/gc.rs b/vm/src/gc.rs
index 878d706a65..9cba332897 100644
--- a/vm/src/gc.rs
+++ b/vm/src/gc.rs
@@ -12,7 +12,7 @@ use std::{
     ptr::{self, NonNull},
     rc::Rc,
     result::Result as StdResult,
-    sync::{Arc, Mutex, RwLock},
+    sync::Arc,
 };
 
 use crate::base::fnv::FnvMap;
@@ -598,24 +598,6 @@ where
     }
 }
 
-unsafe impl<T> Trace for Mutex<T>
-where
-    T: Trace,
-{
-    impl_trace! { self, gc,
-        mark(&*self.lock().unwrap(), gc)
-    }
-}
-
-unsafe impl<T> Trace for RwLock<T>
-where
-    T: Trace,
-{
-    impl_trace! { self, gc,
-        mark(&*self.read().unwrap(), gc)
-    }
-}
-
 unsafe impl<T: ?Sized> Trace for PhantomData<T> {
     impl_trace! { self, _gc, {} }
 }