diff --git a/mmtk/Cargo.lock b/mmtk/Cargo.lock
index 55da681..70769ec 100644
--- a/mmtk/Cargo.lock
+++ b/mmtk/Cargo.lock
@@ -432,7 +432,7 @@ dependencies = [
 [[package]]
 name = "mmtk"
 version = "0.25.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=dccce9063b57dde96d2e97670297aed4dc32e6e1#dccce9063b57dde96d2e97670297aed4dc32e6e1"
+source = "git+https://github.com/mmtk/mmtk-core.git?rev=56b2521d2b99848ee0613a0a5288fe6d81b754ba#56b2521d2b99848ee0613a0a5288fe6d81b754ba"
 dependencies = [
  "atomic",
  "atomic-traits",
@@ -467,7 +467,7 @@ dependencies = [
 [[package]]
 name = "mmtk-macros"
 version = "0.25.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=dccce9063b57dde96d2e97670297aed4dc32e6e1#dccce9063b57dde96d2e97670297aed4dc32e6e1"
+source = "git+https://github.com/mmtk/mmtk-core.git?rev=56b2521d2b99848ee0613a0a5288fe6d81b754ba#56b2521d2b99848ee0613a0a5288fe6d81b754ba"
 dependencies = [
  "proc-macro-error",
  "proc-macro2",
diff --git a/mmtk/Cargo.toml b/mmtk/Cargo.toml
index ad51fff..ee4cc4e 100644
--- a/mmtk/Cargo.toml
+++ b/mmtk/Cargo.toml
@@ -37,7 +37,7 @@ features = ["is_mmtk_object", "object_pinning"]
 
 # Uncomment the following lines to use mmtk-core from the official repository.
 git = "https://github.com/mmtk/mmtk-core.git"
-rev = "dccce9063b57dde96d2e97670297aed4dc32e6e1"
+rev = "56b2521d2b99848ee0613a0a5288fe6d81b754ba"
 
 # Uncomment the following line to use mmtk-core from a local repository.
 # path = "../../mmtk-core"
diff --git a/mmtk/src/lib.rs b/mmtk/src/lib.rs
index af95bb3..05cfa35 100644
--- a/mmtk/src/lib.rs
+++ b/mmtk/src/lib.rs
@@ -12,7 +12,7 @@ use std::thread::ThreadId;
 
 use abi::RubyUpcalls;
 use binding::{RubyBinding, RubyBindingFast, RubyBindingFastMut};
-use mmtk::vm::edge_shape::{SimpleEdge, UnimplementedMemorySlice};
+use mmtk::vm::slot::{SimpleSlot, UnimplementedMemorySlice};
 use mmtk::vm::VMBinding;
 use mmtk::MMTK;
 use once_cell::sync::OnceCell;
@@ -31,15 +31,15 @@ pub mod weak_proc;
 #[derive(Default)]
 pub struct Ruby;
 
-/// Ruby edge type, i.e. a slot that holds a VALUE.
-/// Currently we use SimpleEdge.
-/// It doesn't matter, becaues we have not started using edge-enqueuing, yet.
-pub type RubyEdge = SimpleEdge;
+/// Ruby slot type, i.e. a slot that holds a VALUE.
+/// Currently we use SimpleSlot.
+/// It doesn't matter, becaues we have not started using slot-enqueuing, yet.
+pub type RubySlot = SimpleSlot;
 
 /// Ruby memory slice, i.e. an array of VALUEs.
 /// It is used by array-copy barriers which is supposed to perform bettern than copying array
 /// elements one by one.  At this moment, we just leave it unimplemented.
-pub type RubyMemorySlice = UnimplementedMemorySlice<RubyEdge>;
+pub type RubyMemorySlice = UnimplementedMemorySlice<RubySlot>;
 
 impl VMBinding for Ruby {
     type VMObjectModel = object_model::VMObjectModel;
@@ -48,7 +48,7 @@ impl VMBinding for Ruby {
     type VMActivePlan = active_plan::VMActivePlan;
     type VMReferenceGlue = reference_glue::VMReferenceGlue;
 
-    type VMEdge = RubyEdge;
+    type VMSlot = RubySlot;
     type VMMemorySlice = RubyMemorySlice;
 }
 
diff --git a/mmtk/src/scanning.rs b/mmtk/src/scanning.rs
index f7fa1cb..48c8ed8 100644
--- a/mmtk/src/scanning.rs
+++ b/mmtk/src/scanning.rs
@@ -1,24 +1,24 @@
 use crate::abi::GCThreadTLS;
 
-use crate::{upcalls, Ruby, RubyEdge};
+use crate::{upcalls, Ruby, RubySlot};
 use mmtk::scheduler::GCWorker;
 use mmtk::util::{ObjectReference, VMWorkerThread};
-use mmtk::vm::{EdgeVisitor, ObjectTracer, RootsWorkFactory, Scanning};
+use mmtk::vm::{ObjectTracer, RootsWorkFactory, Scanning, SlotVisitor};
 use mmtk::{Mutator, MutatorContext};
 
 pub struct VMScanning {}
 
 impl Scanning<Ruby> for VMScanning {
-    fn support_edge_enqueuing(_tls: VMWorkerThread, _object: ObjectReference) -> bool {
+    fn support_slot_enqueuing(_tls: VMWorkerThread, _object: ObjectReference) -> bool {
         false
     }
 
-    fn scan_object<EV: EdgeVisitor<RubyEdge>>(
+    fn scan_object<EV: SlotVisitor<RubySlot>>(
         _tls: VMWorkerThread,
         _object: ObjectReference,
-        _edge_visitor: &mut EV,
+        _slot_visitor: &mut EV,
     ) {
-        unreachable!("We have not enabled edge enqueuing for any types, yet.");
+        unreachable!("We have not enabled slot enqueuing for any types, yet.");
     }
 
     fn scan_object_and_trace_edges<OT: ObjectTracer>(
@@ -66,7 +66,7 @@ impl Scanning<Ruby> for VMScanning {
     fn scan_roots_in_mutator_thread(
         tls: VMWorkerThread,
         mutator: &'static mut Mutator<Ruby>,
-        mut factory: impl RootsWorkFactory<RubyEdge>,
+        mut factory: impl RootsWorkFactory<RubySlot>,
     ) {
         let gc_tls = unsafe { GCThreadTLS::from_vwt_check(tls) };
         Self::collect_object_roots_in("scan_thread_root", gc_tls, &mut factory, || {
@@ -74,7 +74,7 @@ impl Scanning<Ruby> for VMScanning {
         });
     }
 
-    fn scan_vm_specific_roots(tls: VMWorkerThread, mut factory: impl RootsWorkFactory<RubyEdge>) {
+    fn scan_vm_specific_roots(tls: VMWorkerThread, mut factory: impl RootsWorkFactory<RubySlot>) {
         let gc_tls = unsafe { GCThreadTLS::from_vwt_check(tls) };
         Self::collect_object_roots_in("scan_vm_specific_roots", gc_tls, &mut factory, || {
             (upcalls().scan_vm_specific_roots)();
@@ -114,7 +114,7 @@ impl VMScanning {
     fn collect_object_roots_in<F: FnMut()>(
         root_scan_kind: &str,
         gc_tls: &mut GCThreadTLS,
-        factory: &mut impl RootsWorkFactory<RubyEdge>,
+        factory: &mut impl RootsWorkFactory<RubySlot>,
         callback: F,
     ) {
         let mut buffer: Vec<ObjectReference> = Vec::new();