diff --git a/src/librustc_mir/const_eval.rs b/src/librustc_mir/const_eval.rs
index aa264bbd4bb5c..e95ef0caaafaf 100644
--- a/src/librustc_mir/const_eval.rs
+++ b/src/librustc_mir/const_eval.rs
@@ -47,7 +47,7 @@ pub(crate) fn mk_eval_cx<'mir, 'tcx>(
     param_env: ty::ParamEnv<'tcx>,
 ) -> CompileTimeEvalContext<'mir, 'tcx> {
     debug!("mk_eval_cx: {:?}", param_env);
-    InterpCx::new(tcx.at(span), param_env, CompileTimeInterpreter::new())
+    InterpCx::new(tcx.at(span), param_env, CompileTimeInterpreter::new(), Default::default())
 }
 
 pub(crate) fn eval_promoted<'mir, 'tcx>(
@@ -632,7 +632,12 @@ pub fn const_eval_raw_provider<'tcx>(
     }
 
     let span = tcx.def_span(cid.instance.def_id());
-    let mut ecx = InterpCx::new(tcx.at(span), key.param_env, CompileTimeInterpreter::new());
+    let mut ecx = InterpCx::new(
+        tcx.at(span),
+        key.param_env,
+        CompileTimeInterpreter::new(),
+        Default::default()
+    );
 
     let res = ecx.load_mir(cid.instance.def);
     res.map(|body| {
diff --git a/src/librustc_mir/interpret/eval_context.rs b/src/librustc_mir/interpret/eval_context.rs
index e24fa6351e5df..fd5290ee0400c 100644
--- a/src/librustc_mir/interpret/eval_context.rs
+++ b/src/librustc_mir/interpret/eval_context.rs
@@ -196,12 +196,17 @@ impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> LayoutOf for InterpCx<'mir, 'tcx, M> {
 }
 
 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
-    pub fn new(tcx: TyCtxtAt<'tcx>, param_env: ty::ParamEnv<'tcx>, machine: M) -> Self {
+    pub fn new(
+        tcx: TyCtxtAt<'tcx>,
+        param_env: ty::ParamEnv<'tcx>,
+        machine: M,
+        memory_extra: M::MemoryExtra,
+    ) -> Self {
         InterpCx {
             machine,
             tcx,
             param_env,
-            memory: Memory::new(tcx),
+            memory: Memory::new(tcx, memory_extra),
             stack: Vec::new(),
             vtables: FxHashMap::default(),
         }
diff --git a/src/librustc_mir/interpret/machine.rs b/src/librustc_mir/interpret/machine.rs
index f16c21857b987..ff560360f0ad1 100644
--- a/src/librustc_mir/interpret/machine.rs
+++ b/src/librustc_mir/interpret/machine.rs
@@ -73,7 +73,7 @@ pub trait Machine<'mir, 'tcx>: Sized {
     /// Extra data stored in memory. A reference to this is available when `AllocExtra`
     /// gets initialized, so you can e.g., have an `Rc` here if there is global state you
     /// need access to in the `AllocExtra` hooks.
-    type MemoryExtra: Default;
+    type MemoryExtra;
 
     /// Extra data stored in every allocation.
     type AllocExtra: AllocationExtra<Self::PointerTag> + 'static;
diff --git a/src/librustc_mir/interpret/memory.rs b/src/librustc_mir/interpret/memory.rs
index 5b177d05bb862..f5d912595337b 100644
--- a/src/librustc_mir/interpret/memory.rs
+++ b/src/librustc_mir/interpret/memory.rs
@@ -106,11 +106,11 @@ where
 }
 
 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
-    pub fn new(tcx: TyCtxtAt<'tcx>) -> Self {
+    pub fn new(tcx: TyCtxtAt<'tcx>, extra: M::MemoryExtra) -> Self {
         Memory {
             alloc_map: M::MemoryMap::default(),
             dead_alloc_map: FxHashMap::default(),
-            extra: M::MemoryExtra::default(),
+            extra,
             tcx,
         }
     }