diff --git a/src/librustc/mir/mod.rs b/src/librustc/mir/mod.rs
index 9ac1465cb0ba..b0830fb72eb0 100644
--- a/src/librustc/mir/mod.rs
+++ b/src/librustc/mir/mod.rs
@@ -37,7 +37,7 @@ use std::slice;
 use std::vec::IntoIter;
 use std::{iter, mem, option, u32};
 use syntax::ast::Name;
-use syntax::symbol::{InternedString, Symbol};
+use syntax::symbol::Symbol;
 use syntax_pos::{Span, DUMMY_SP};
 
 pub use crate::mir::interpret::AssertMessage;
@@ -2736,8 +2736,8 @@ pub enum UnsafetyViolationKind {
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable, HashStable)]
 pub struct UnsafetyViolation {
     pub source_info: SourceInfo,
-    pub description: InternedString,
-    pub details: InternedString,
+    pub description: Symbol,
+    pub details: Symbol,
     pub kind: UnsafetyViolationKind,
 }
 
diff --git a/src/librustc_mir/transform/check_unsafety.rs b/src/librustc_mir/transform/check_unsafety.rs
index 70855d70228b..3ff36e01275b 100644
--- a/src/librustc_mir/transform/check_unsafety.rs
+++ b/src/librustc_mir/transform/check_unsafety.rs
@@ -12,7 +12,7 @@ use rustc::lint::builtin::{SAFE_EXTERN_STATICS, SAFE_PACKED_BORROWS, UNUSED_UNSA
 use rustc::mir::*;
 use rustc::mir::visit::{PlaceContext, Visitor, MutatingUseContext};
 
-use syntax::symbol::{InternedString, sym};
+use syntax::symbol::{Symbol, sym};
 
 use std::ops::Bound;
 
@@ -167,9 +167,8 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
                     (CastTy::FnPtr, CastTy::Int(_)) => {
                         self.register_violations(&[UnsafetyViolation {
                             source_info: self.source_info,
-                            description: InternedString::intern("cast of pointer to int"),
-                            details: InternedString::intern(
-                                "casting pointers to integers in constants"),
+                            description: Symbol::intern("cast of pointer to int"),
+                            details: Symbol::intern("casting pointers to integers in constants"),
                             kind: UnsafetyViolationKind::General,
                         }], &[]);
                     },
@@ -185,8 +184,8 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
                 if let ty::RawPtr(_) | ty::FnPtr(..) = lhs.ty(self.body, self.tcx).kind {
                     self.register_violations(&[UnsafetyViolation {
                         source_info: self.source_info,
-                        description: InternedString::intern("pointer operation"),
-                        details: InternedString::intern("operations on pointers in constants"),
+                        description: Symbol::intern("pointer operation"),
+                        details: Symbol::intern("operations on pointers in constants"),
                         kind: UnsafetyViolationKind::General,
                     }], &[]);
                 }
@@ -219,8 +218,8 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
                         self.source_scope_local_data[source_info.scope].lint_root;
                     self.register_violations(&[UnsafetyViolation {
                         source_info,
-                        description: InternedString::intern("use of extern static"),
-                        details: InternedString::intern(
+                        description: Symbol::intern("use of extern static"),
+                        details: Symbol::intern(
                             "extern statics are not controlled by the Rust type system: \
                             invalid data, aliasing violations or data races will cause \
                             undefined behavior"),
@@ -240,8 +239,8 @@ impl<'a, 'tcx> Visitor<'tcx> for UnsafetyChecker<'a, 'tcx> {
                         self.source_scope_local_data[source_info.scope].lint_root;
                     self.register_violations(&[UnsafetyViolation {
                         source_info,
-                        description: InternedString::intern("borrow of packed field"),
-                        details: InternedString::intern(
+                        description: Symbol::intern("borrow of packed field"),
+                        details: Symbol::intern(
                             "fields of packed structs might be misaligned: dereferencing a \
                             misaligned pointer or even just creating a misaligned reference \
                             is undefined behavior"),
@@ -334,8 +333,8 @@ impl<'a, 'tcx> UnsafetyChecker<'a, 'tcx> {
         let source_info = self.source_info;
         self.register_violations(&[UnsafetyViolation {
             source_info,
-            description: InternedString::intern(description),
-            details: InternedString::intern(details),
+            description: Symbol::intern(description),
+            details: Symbol::intern(details),
             kind,
         }], &[]);
     }
@@ -438,8 +437,8 @@ impl<'a, 'tcx> UnsafetyChecker<'a, 'tcx> {
                                 let source_info = self.source_info;
                                 self.register_violations(&[UnsafetyViolation {
                                     source_info,
-                                    description: InternedString::intern(description),
-                                    details: InternedString::intern(details),
+                                    description: Symbol::intern(description),
+                                    details: Symbol::intern(details),
                                     kind: UnsafetyViolationKind::GeneralAndConstFn,
                                 }], &[]);
                             }