diff --git a/compiler/rustc_query_system/src/cache.rs b/compiler/rustc_middle/src/traits/cache.rs
similarity index 100%
rename from compiler/rustc_query_system/src/cache.rs
rename to compiler/rustc_middle/src/traits/cache.rs
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 3a1682614cbf..75323bf5c8cc 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -2,6 +2,7 @@
 //!
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/traits/resolution.html
 
+pub mod cache;
 pub mod query;
 pub mod select;
 pub mod solve;
diff --git a/compiler/rustc_middle/src/traits/select.rs b/compiler/rustc_middle/src/traits/select.rs
index 3861efd36428..f151a6e4567e 100644
--- a/compiler/rustc_middle/src/traits/select.rs
+++ b/compiler/rustc_middle/src/traits/select.rs
@@ -5,12 +5,12 @@
 use rustc_errors::ErrorGuaranteed;
 use rustc_hir::def_id::DefId;
 use rustc_macros::{HashStable, TypeVisitable};
-use rustc_query_system::cache::Cache;
 use rustc_type_ir::solve::AliasBoundKind;
 
 use self::EvaluationResult::*;
 use super::{SelectionError, SelectionResult};
 use crate::ty;
+use crate::traits::cache::Cache;
 
 pub type SelectionCache<'tcx, ENV> =
     Cache<(ENV, ty::TraitPredicate<'tcx>), SelectionResult<'tcx, SelectionCandidate<'tcx>>>;
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 41e1388e3146..b283c08b90de 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -40,7 +40,6 @@ use rustc_hir::lang_items::LangItem;
 use rustc_hir::limit::Limit;
 use rustc_hir::{self as hir, HirId, Node, TraitCandidate, find_attr};
 use rustc_index::IndexVec;
-use rustc_query_system::cache::WithDepNode;
 use rustc_query_system::dep_graph::DepNodeIndex;
 use rustc_query_system::ich::StableHashingContext;
 use rustc_serialize::opaque::{FileEncodeResult, FileEncoder};
@@ -71,6 +70,7 @@ use crate::query::plumbing::QuerySystem;
 use crate::query::{IntoQueryParam, LocalCrate, Providers, TyCtxtAt};
 use crate::thir::Thir;
 use crate::traits;
+use crate::traits::cache::WithDepNode;
 use crate::traits::solve::{
     self, CanonicalInput, ExternalConstraints, ExternalConstraintsData, PredefinedOpaques,
     QueryResult, inspect,
diff --git a/compiler/rustc_query_system/src/lib.rs b/compiler/rustc_query_system/src/lib.rs
index 61edf397886b..b61b9b71b528 100644
--- a/compiler/rustc_query_system/src/lib.rs
+++ b/compiler/rustc_query_system/src/lib.rs
@@ -5,7 +5,6 @@
 #![feature(min_specialization)]
 // tidy-alphabetical-end
 
-pub mod cache;
 pub mod dep_graph;
 mod error;
 pub mod ich;