diff --git a/src/librustc_mir/borrow_check/nll/constraint_set.rs b/src/librustc_mir/borrow_check/nll/constraints/mod.rs
similarity index 100%
rename from src/librustc_mir/borrow_check/nll/constraint_set.rs
rename to src/librustc_mir/borrow_check/nll/constraints/mod.rs
diff --git a/src/librustc_mir/borrow_check/nll/mod.rs b/src/librustc_mir/borrow_check/nll/mod.rs
index 1891cac268c5..26298a289fc6 100644
--- a/src/librustc_mir/borrow_check/nll/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/mod.rs
@@ -45,7 +45,7 @@ mod renumber;
 crate mod type_check;
 mod universal_regions;
 
-crate mod constraint_set;
+mod constraints;
 
 use self::facts::AllFacts;
 use self::region_infer::RegionInferenceContext;
diff --git a/src/librustc_mir/borrow_check/nll/region_infer/graphviz.rs b/src/librustc_mir/borrow_check/nll/region_infer/graphviz.rs
index 0116fbcfc886..8be51257cd6c 100644
--- a/src/librustc_mir/borrow_check/nll/region_infer/graphviz.rs
+++ b/src/librustc_mir/borrow_check/nll/region_infer/graphviz.rs
@@ -17,7 +17,7 @@ use rustc_data_structures::indexed_vec::Idx;
 use std::borrow::Cow;
 use std::io::{self, Write};
 use super::*;
-use borrow_check::nll::constraint_set::OutlivesConstraint;
+use borrow_check::nll::constraints::OutlivesConstraint;
 
 
 impl<'tcx> RegionInferenceContext<'tcx> {
diff --git a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
index f0ada4a85a14..e4426ff3869e 100644
--- a/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/region_infer/mod.rs
@@ -9,7 +9,7 @@
 // except according to those terms.
 
 use super::universal_regions::UniversalRegions;
-use borrow_check::nll::constraint_set::{
+use borrow_check::nll::constraints::{
     ConstraintIndex, ConstraintGraph, ConstraintSet, OutlivesConstraint
 };
 use borrow_check::nll::type_check::Locations;
diff --git a/src/librustc_mir/borrow_check/nll/type_check/constraint_conversion.rs b/src/librustc_mir/borrow_check/nll/type_check/constraint_conversion.rs
index a5a159fbb1c3..64a61972a220 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/constraint_conversion.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/constraint_conversion.rs
@@ -9,12 +9,11 @@
 // except according to those terms.
 
 use borrow_check::location::LocationTable;
-use borrow_check::nll::constraint_set::OutlivesConstraint;
+use borrow_check::nll::constraints::{ConstraintSet, OutlivesConstraint};
 use borrow_check::nll::facts::AllFacts;
 use borrow_check::nll::region_infer::{RegionTest, TypeTest};
 use borrow_check::nll::type_check::Locations;
 use borrow_check::nll::universal_regions::UniversalRegions;
-use borrow_check::nll::constraint_set::ConstraintSet;
 use rustc::infer::canonical::QueryRegionConstraint;
 use rustc::infer::outlives::obligations::{TypeOutlives, TypeOutlivesDelegate};
 use rustc::infer::region_constraints::{GenericKind, VerifyBound};
diff --git a/src/librustc_mir/borrow_check/nll/type_check/mod.rs b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
index 97a74e0d3365..25f2be231772 100644
--- a/src/librustc_mir/borrow_check/nll/type_check/mod.rs
+++ b/src/librustc_mir/borrow_check/nll/type_check/mod.rs
@@ -13,7 +13,7 @@
 
 use borrow_check::borrow_set::BorrowSet;
 use borrow_check::location::LocationTable;
-use borrow_check::nll::constraint_set::{ConstraintSet, OutlivesConstraint};
+use borrow_check::nll::constraints::{ConstraintSet, OutlivesConstraint};
 use borrow_check::nll::facts::AllFacts;
 use borrow_check::nll::region_infer::{ClosureRegionRequirementsExt, TypeTest};
 use borrow_check::nll::universal_regions::UniversalRegions;