diff --git a/mmtk/Cargo.toml b/mmtk/Cargo.toml
index ba91f9d5..29e28a66 100644
--- a/mmtk/Cargo.toml
+++ b/mmtk/Cargo.toml
@@ -30,7 +30,7 @@ once_cell = "1.10.0"
 # - change branch
 # - change repo name
 # But other changes including adding/removing whitespaces in commented lines may break the CI.
-mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "2ec37bde7955304f3e4bc5f7bed3fbfba3833cc0" }
+mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "f1a0bb7fbec97dd84e35a40e8be01cf5018f2f9e" }
 # Uncomment the following to build locally
 # mmtk = { path = "../repos/mmtk-core" }
 
diff --git a/mmtk/src/lib.rs b/mmtk/src/lib.rs
index d4847d5c..e501c64f 100644
--- a/mmtk/src/lib.rs
+++ b/mmtk/src/lib.rs
@@ -98,8 +98,8 @@ pub struct OpenJDK_Upcalls {
     pub referent_offset: extern "C" fn() -> i32,
     pub discovered_offset: extern "C" fn() -> i32,
     pub dump_object_string: extern "C" fn(object: ObjectReference) -> *const c_char,
-    pub scan_all_thread_roots: extern "C" fn(closure: EdgesClosure),
-    pub scan_thread_roots: extern "C" fn(closure: EdgesClosure, tls: VMMutatorThread),
+    pub scan_roots_in_all_mutator_threads: extern "C" fn(closure: EdgesClosure),
+    pub scan_roots_in_mutator_thread: extern "C" fn(closure: EdgesClosure, tls: VMMutatorThread),
     pub scan_universe_roots: extern "C" fn(closure: EdgesClosure),
     pub scan_jni_handle_roots: extern "C" fn(closure: EdgesClosure),
     pub scan_object_synchronizer_roots: extern "C" fn(closure: EdgesClosure),
diff --git a/mmtk/src/scanning.rs b/mmtk/src/scanning.rs
index 17192e9c..aa1a5dba 100644
--- a/mmtk/src/scanning.rs
+++ b/mmtk/src/scanning.rs
@@ -58,20 +58,23 @@ impl Scanning<OpenJDK> for VMScanning {
         // TODO
     }
 
-    fn scan_thread_roots(_tls: VMWorkerThread, mut factory: impl RootsWorkFactory<OpenJDKEdge>) {
+    fn scan_roots_in_all_mutator_threads(
+        _tls: VMWorkerThread,
+        mut factory: impl RootsWorkFactory<OpenJDKEdge>,
+    ) {
         unsafe {
-            ((*UPCALLS).scan_all_thread_roots)(to_edges_closure(&mut factory));
+            ((*UPCALLS).scan_roots_in_all_mutator_threads)(to_edges_closure(&mut factory));
         }
     }
 
-    fn scan_thread_root(
+    fn scan_roots_in_mutator_thread(
         _tls: VMWorkerThread,
         mutator: &'static mut Mutator<OpenJDK>,
         mut factory: impl RootsWorkFactory<OpenJDKEdge>,
     ) {
         let tls = mutator.get_tls();
         unsafe {
-            ((*UPCALLS).scan_thread_roots)(to_edges_closure(&mut factory), tls);
+            ((*UPCALLS).scan_roots_in_mutator_thread)(to_edges_closure(&mut factory), tls);
         }
     }
 
diff --git a/openjdk/mmtk.h b/openjdk/mmtk.h
index 1f6076ce..88c96d49 100644
--- a/openjdk/mmtk.h
+++ b/openjdk/mmtk.h
@@ -163,8 +163,8 @@ typedef struct {
     int (*referent_offset) ();
     int (*discovered_offset) ();
     char* (*dump_object_string) (void* object);
-    void (*scan_all_thread_roots)(EdgesClosure closure);
-    void (*scan_thread_roots)(EdgesClosure closure, void* tls);
+    void (*scan_roots_in_all_mutator_threads)(EdgesClosure closure);
+    void (*scan_roots_in_mutator_thread)(EdgesClosure closure, void* tls);
     void (*scan_universe_roots) (EdgesClosure closure);
     void (*scan_jni_handle_roots) (EdgesClosure closure);
     void (*scan_object_synchronizer_roots) (EdgesClosure closure);
diff --git a/openjdk/mmtkHeap.cpp b/openjdk/mmtkHeap.cpp
index 6a573f74..4197f64d 100644
--- a/openjdk/mmtkHeap.cpp
+++ b/openjdk/mmtkHeap.cpp
@@ -415,7 +415,7 @@ void MMTkHeap::scan_vm_thread_roots(OopClosure& cl) {
   VMThread::vm_thread()->oops_do(&cl, NULL);
 }
 
-void MMTkHeap::scan_thread_roots(OopClosure& cl) {
+void MMTkHeap::scan_roots_in_all_mutator_threads(OopClosure& cl) {
   ResourceMark rm;
   Threads::possibly_parallel_oops_do(false, &cl, NULL);
 }
diff --git a/openjdk/mmtkHeap.hpp b/openjdk/mmtkHeap.hpp
index 55369244..e01dfaf9 100644
--- a/openjdk/mmtkHeap.hpp
+++ b/openjdk/mmtkHeap.hpp
@@ -195,7 +195,7 @@ class MMTkHeap : public CollectedHeap {
 
   void scan_roots(OopClosure& cl);
 
-  void scan_thread_roots(OopClosure& cl);
+  void scan_roots_in_all_mutator_threads(OopClosure& cl);
 
   void scan_universe_roots(OopClosure& cl);
   void scan_jni_handle_roots(OopClosure& cl);
diff --git a/openjdk/mmtkUpcalls.cpp b/openjdk/mmtkUpcalls.cpp
index 7059a0ca..5f1350d0 100644
--- a/openjdk/mmtkUpcalls.cpp
+++ b/openjdk/mmtkUpcalls.cpp
@@ -184,12 +184,12 @@ static void mmtk_get_mutators(MutatorClosure closure) {
   }
 }
 
-static void mmtk_scan_all_thread_roots(EdgesClosure closure) {
+static void mmtk_scan_roots_in_all_mutator_threads(EdgesClosure closure) {
   MMTkRootsClosure2 cl(closure);
-  MMTkHeap::heap()->scan_thread_roots(cl);
+  MMTkHeap::heap()->scan_roots_in_all_mutator_threads(cl);
 }
 
-static void mmtk_scan_thread_roots(EdgesClosure closure, void* tls) {
+static void mmtk_scan_roots_in_mutator_thread(EdgesClosure closure, void* tls) {
   ResourceMark rm;
   JavaThread* thread = (JavaThread*) tls;
   MMTkRootsClosure2 cl(closure);
@@ -334,8 +334,8 @@ OpenJDK_Upcalls mmtk_upcalls = {
   referent_offset,
   discovered_offset,
   dump_object_string,
-  mmtk_scan_all_thread_roots,
-  mmtk_scan_thread_roots,
+  mmtk_scan_roots_in_all_mutator_threads,
+  mmtk_scan_roots_in_mutator_thread,
   mmtk_scan_universe_roots,
   mmtk_scan_jni_handle_roots,
   mmtk_scan_object_synchronizer_roots,