diff --git a/mmtk/Cargo.lock b/mmtk/Cargo.lock
index 9d5038fd..cf6e8a44 100644
--- a/mmtk/Cargo.lock
+++ b/mmtk/Cargo.lock
@@ -86,9 +86,9 @@ checksum = "7f30e7476521f6f8af1a1c4c0b8cc94f0bee37d91763d0ca2665f299b6cd8aec"
 
 [[package]]
 name = "bytemuck"
-version = "1.14.0"
+version = "1.14.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "374d28ec25809ee0e23827c2ab573d729e293f281dfe393500e7ad618baa61c6"
+checksum = "ea31d69bda4949c1c1562c1e6f042a1caefac98cdc8a298260a2ff41c1e2d42b"
 dependencies = [
  "bytemuck_derive",
 ]
@@ -122,16 +122,16 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "chrono"
-version = "0.4.31"
+version = "0.4.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f2c685bad3eb3d45a01354cedb7d5faa66194d1d58ba6e267a8de788f79db38"
+checksum = "9f13690e35a5e4ace198e7beea2895d29f3a9cc55015fcebe6336bd2010af9eb"
 dependencies = [
  "android-tzdata",
  "iana-time-zone",
  "js-sys",
  "num-traits",
  "wasm-bindgen",
- "windows-targets 0.48.5",
+ "windows-targets",
 ]
 
 [[package]]
@@ -241,9 +241,9 @@ dependencies = [
 
 [[package]]
 name = "env_logger"
-version = "0.10.1"
+version = "0.10.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95b3f3e67048839cb0d0781f445682a35113da7121f7c949db0e2be96a4fbece"
+checksum = "4cd405aab171cb85d6735e5c8d9db038c17d3ca007a4d2c25f337935c3d90580"
 dependencies = [
  "humantime",
  "is-terminal",
@@ -273,9 +273,9 @@ dependencies = [
 
 [[package]]
 name = "git2"
-version = "0.18.1"
+version = "0.18.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fbf97ba92db08df386e10c8ede66a2a0369bd277090afd8710e19e38de9ec0cd"
+checksum = "1b3ba52851e73b46a4c3df1d89343741112003f0f6f13beb0dfac9e457c3fdcd"
 dependencies = [
  "bitflags",
  "libc",
@@ -292,9 +292,9 @@ checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 
 [[package]]
 name = "hermit-abi"
-version = "0.3.4"
+version = "0.3.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d3d0e0f38255e7fa3cf31335b3a56f05febd18025f4db5ef7a0cfb4f8da651f"
+checksum = "d0c62115964e08cb8039170eb33c1d0e2388a256930279edca206fff675f82c3"
 
 [[package]]
 name = "humantime"
@@ -304,9 +304,9 @@ checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
 [[package]]
 name = "iana-time-zone"
-version = "0.1.59"
+version = "0.1.60"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6a67363e2aa4443928ce15e57ebae94fd8949958fd1223c4cfc0cd473ad7539"
+checksum = "e7ffbb5a1b541ea2561f8c41c087286cc091e21e556a4f09a8f6cbf17b69b141"
 dependencies = [
  "android_system_properties",
  "core-foundation-sys",
@@ -348,27 +348,27 @@ dependencies = [
 
 [[package]]
 name = "itertools"
-version = "0.12.0"
+version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25db6b064527c5d482d0423354fcd07a89a2dfe07b67892e62411946db7f07b0"
+checksum = "ba291022dbbd398a455acf126c1e341954079855bc60dfdda641363bd6922569"
 dependencies = [
  "either",
 ]
 
 [[package]]
 name = "jobserver"
-version = "0.1.27"
+version = "0.1.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c37f63953c4c63420ed5fd3d6d398c719489b9f872b9fa683262f8edd363c7d"
+checksum = "ab46a6e9526ddef3ae7f787c06f0f2600639ba80ea3eade3d8e670a2230f51d6"
 dependencies = [
  "libc",
 ]
 
 [[package]]
 name = "js-sys"
-version = "0.3.67"
+version = "0.3.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a1d36f1235bc969acba30b7f5990b864423a6068a10f7c90ae8f0112e3a59d1"
+checksum = "406cda4b368d531c842222cf9d2600a9a4acce8d29423695379c6868a143a9ee"
 dependencies = [
  "wasm-bindgen",
 ]
@@ -381,15 +381,15 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.152"
+version = "0.2.153"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13e3bf6590cbc649f4d1a3eefc9d5d6eb746f5200ffb04e5e142700b8faa56e7"
+checksum = "9c198f91728a82281a64e1f4f9eeb25d82cb32a5de251c6bd1b5154d63a8e7bd"
 
 [[package]]
 name = "libgit2-sys"
-version = "0.16.1+1.7.1"
+version = "0.16.2+1.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2a2bb3680b094add03bb3732ec520ece34da31a8cd2d633d1389d0f0fb60d0c"
+checksum = "ee4126d8b4ee5c9d9ea891dd875cfdc1e9d0950437179104b183d7d8a74d24e8"
 dependencies = [
  "cc",
  "libc",
@@ -399,9 +399,9 @@ dependencies = [
 
 [[package]]
 name = "libz-sys"
-version = "1.1.14"
+version = "1.1.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "295c17e837573c8c821dbaeb3cceb3d745ad082f7572191409e69cbc1b3fd050"
+checksum = "037731f5d3aaa87a5675e895b63ddff1a87624bc29f77004ea829809654e48f6"
 dependencies = [
  "cc",
  "libc",
@@ -449,7 +449,7 @@ dependencies = [
 [[package]]
 name = "mmtk"
 version = "0.22.1"
-source = "git+https://github.com/udesou/mmtk-core.git?rev=9da979de09a24f4524011e0d9086e1bba43fa9d7#9da979de09a24f4524011e0d9086e1bba43fa9d7"
+source = "git+https://github.com/mmtk/mmtk-core.git?rev=7cafe560139211c0e3a74815d2e288278506099d#7cafe560139211c0e3a74815d2e288278506099d"
 dependencies = [
  "atomic 0.6.0",
  "atomic-traits",
@@ -500,7 +500,7 @@ dependencies = [
 [[package]]
 name = "mmtk-macros"
 version = "0.22.1"
-source = "git+https://github.com/udesou/mmtk-core.git?rev=9da979de09a24f4524011e0d9086e1bba43fa9d7#9da979de09a24f4524011e0d9086e1bba43fa9d7"
+source = "git+https://github.com/mmtk/mmtk-core.git?rev=7cafe560139211c0e3a74815d2e288278506099d#7cafe560139211c0e3a74815d2e288278506099d"
 dependencies = [
  "proc-macro-error",
  "proc-macro2",
@@ -519,9 +519,9 @@ dependencies = [
 
 [[package]]
 name = "num-traits"
-version = "0.2.17"
+version = "0.2.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "39e3200413f237f41ab11ad6d161bc7239c84dcb631773ccd7de3dfe4b5c267c"
+checksum = "da0df0e5185db44f69b44f26786fe401b6c293d1907744beaa7fa62b2e5a517a"
 dependencies = [
  "autocfg",
 ]
@@ -550,9 +550,9 @@ checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
 [[package]]
 name = "pest"
-version = "2.7.6"
+version = "2.7.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1f200d8d83c44a45b21764d1916299752ca035d15ecd46faca3e9a2a2bf6ad06"
+checksum = "219c0dcc30b6a27553f9cc242972b67f75b60eb0db71f0b5462f38b058c41546"
 dependencies = [
  "memchr",
  "thiserror",
@@ -603,9 +603,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.76"
+version = "1.0.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "95fc56cda0b5c3325f5fbbd7ff9fda9e02bb00bb3dac51252d2f1bfa1cb8cc8c"
+checksum = "e2422ad645d89c99f8f3e6b88a9fdeca7fabeac836b1002371c4367c8f984aae"
 dependencies = [
  "unicode-ident",
 ]
@@ -641,9 +641,9 @@ dependencies = [
 
 [[package]]
 name = "regex"
-version = "1.10.2"
+version = "1.10.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "380b951a9c5e80ddfd6136919eef32310721aa4aacd4889a8d39124b026ab343"
+checksum = "b62dbe01f0b06f9d8dc7d49e05a0785f153b00b2c227856282f671e0318c9b15"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -653,9 +653,9 @@ dependencies = [
 
 [[package]]
 name = "regex-automata"
-version = "0.4.3"
+version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f804c7828047e88b2d32e2d7fe5a105da8ee3264f01902f796c8e067dc2483f"
+checksum = "5bb987efffd3c6d0d8f5f89510bb458559eab11e4f869acb20bf845e016259cd"
 dependencies = [
  "aho-corasick",
  "memchr",
@@ -679,9 +679,9 @@ dependencies = [
 
 [[package]]
 name = "rustix"
-version = "0.38.30"
+version = "0.38.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "322394588aaf33c24007e8bb3238ee3e4c5c09c084ab32bc73890b99ff326bca"
+checksum = "6ea3e1a662af26cd7a3ba09c0297a31af215563ecf42817c98df621387f4e949"
 dependencies = [
  "bitflags",
  "errno",
@@ -897,9 +897,9 @@ checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.90"
+version = "0.2.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b1223296a201415c7fad14792dbefaace9bd52b62d33453ade1c5b5f07555406"
+checksum = "c1e124130aee3fb58c5bdd6b639a0509486b0338acaaae0c84a5124b0f588b7f"
 dependencies = [
  "cfg-if",
  "wasm-bindgen-macro",
@@ -907,9 +907,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.90"
+version = "0.2.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fcdc935b63408d58a32f8cc9738a0bffd8f05cc7c002086c6ef20b7312ad9dcd"
+checksum = "c9e7e1900c352b609c8488ad12639a311045f40a35491fb69ba8c12f758af70b"
 dependencies = [
  "bumpalo",
  "log",
@@ -922,9 +922,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.90"
+version = "0.2.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3e4c238561b2d428924c49815533a8b9121c664599558a5d9ec51f8a1740a999"
+checksum = "b30af9e2d358182b5c7449424f017eba305ed32a7010509ede96cdc4696c46ed"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -932,9 +932,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.90"
+version = "0.2.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bae1abb6806dc1ad9e560ed242107c0f6c84335f1749dd4e8ddb012ebd5e25a7"
+checksum = "642f325be6301eb8107a83d12a8ac6c1e1c54345a7ef1a9261962dfefda09e66"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -945,9 +945,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.90"
+version = "0.2.91"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4d91413b1c31d7539ba5ef2451af3f0b833a005eb27a631cec32bc0635a8602b"
+checksum = "4f186bd2dcf04330886ce82d6f33dd75a7bfcf69ecf5763b89fcde53b6ac9838"
 
 [[package]]
 name = "winapi"
@@ -986,7 +986,7 @@ version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "33ab640c8d7e35bf8ba19b884ba838ceb4fba93a4e8c65a9059d08afcfc683d9"
 dependencies = [
- "windows-targets 0.52.0",
+ "windows-targets",
 ]
 
 [[package]]
@@ -995,22 +995,7 @@ version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
 dependencies = [
- "windows-targets 0.52.0",
-]
-
-[[package]]
-name = "windows-targets"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
-dependencies = [
- "windows_aarch64_gnullvm 0.48.5",
- "windows_aarch64_msvc 0.48.5",
- "windows_i686_gnu 0.48.5",
- "windows_i686_msvc 0.48.5",
- "windows_x86_64_gnu 0.48.5",
- "windows_x86_64_gnullvm 0.48.5",
- "windows_x86_64_msvc 0.48.5",
+ "windows-targets",
 ]
 
 [[package]]
@@ -1019,93 +1004,51 @@ version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8a18201040b24831fbb9e4eb208f8892e1f50a37feb53cc7ff887feb8f50e7cd"
 dependencies = [
- "windows_aarch64_gnullvm 0.52.0",
- "windows_aarch64_msvc 0.52.0",
- "windows_i686_gnu 0.52.0",
- "windows_i686_msvc 0.52.0",
- "windows_x86_64_gnu 0.52.0",
- "windows_x86_64_gnullvm 0.52.0",
- "windows_x86_64_msvc 0.52.0",
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
 ]
 
-[[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
-
 [[package]]
 name = "windows_aarch64_gnullvm"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cb7764e35d4db8a7921e09562a0304bf2f93e0a51bfccee0bd0bb0b666b015ea"
 
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
-
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbaa0368d4f1d2aaefc55b6fcfee13f41544ddf36801e793edbbfd7d7df075ef"
 
-[[package]]
-name = "windows_i686_gnu"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
-
 [[package]]
 name = "windows_i686_gnu"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a28637cb1fa3560a16915793afb20081aba2c92ee8af57b4d5f28e4b3e7df313"
 
-[[package]]
-name = "windows_i686_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
-
 [[package]]
 name = "windows_i686_msvc"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ffe5e8e31046ce6230cc7215707b816e339ff4d4d67c65dffa206fd0f7aa7b9a"
 
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
-
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d6fa32db2bc4a2f5abeacf2b69f7992cd09dca97498da74a151a3132c26befd"
 
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
-
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1a657e1e9d3f514745a572a6846d3c7aa7dbe1658c056ed9c3344c4109a6949e"
 
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
-
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.52.0"
diff --git a/mmtk/Cargo.toml b/mmtk/Cargo.toml
index 35f65575..711cb4a7 100644
--- a/mmtk/Cargo.toml
+++ b/mmtk/Cargo.toml
@@ -31,7 +31,7 @@ lazy_static = "1.1"
 # - change branch
 # - change repo name
 # But other changes including adding/removing whitespaces in commented lines may break the CI
-mmtk = { git = "https://github.com/udesou/mmtk-core.git", rev="9da979de09a24f4524011e0d9086e1bba43fa9d7" }
+mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev="7cafe560139211c0e3a74815d2e288278506099d" }
 # Uncomment the following to build locally
 # mmtk = { path = "../../mmtk-core" }
 log = {version = "0.4", features = ["max_level_trace", "release_max_level_off"] }
diff --git a/mmtk/src/collection.rs b/mmtk/src/collection.rs
index c2c35c36..e25203d4 100644
--- a/mmtk/src/collection.rs
+++ b/mmtk/src/collection.rs
@@ -111,16 +111,8 @@ impl Collection<JuliaVM> for VMCollection {
         crate::api::JULIA_MALLOC_BYTES.load(Ordering::SeqCst)
     }
 
-    #[inline(always)]
-    fn is_collection_disabled() -> bool {
-        unsafe {
-            AtomicU32::load(
-                ::std::mem::transmute::<*const AtomicU32, &AtomicU32>(::std::ptr::addr_of!(
-                    jl_gc_disable_counter
-                )),
-                Ordering::SeqCst,
-            ) > 0
-        }
+    fn is_collection_enabled() -> bool {
+        unsafe { AtomicU32::load(&jl_gc_disable_counter, Ordering::SeqCst) <= 0 }
     }
 }