diff --git a/mmtk/Cargo.lock b/mmtk/Cargo.lock
index 6c8d602..d5d0d6a 100644
--- a/mmtk/Cargo.lock
+++ b/mmtk/Cargo.lock
@@ -94,9 +94,9 @@ checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "bitflags"
-version = "2.9.3"
+version = "2.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34efbcccd345379ca2868b2b2c9d3782e9cc58ba87bc7d79d5b53d9c9ae6f25d"
+checksum = "2261d10cca569e4643e526d8dc2e62e433cc8aba21ab764233731f8d369bf394"
 
 [[package]]
 name = "built"
@@ -129,10 +129,11 @@ dependencies = [
 
 [[package]]
 name = "cc"
-version = "1.2.34"
+version = "1.2.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42bc4aea80032b7bf409b0bc7ccad88853858911b7713a8062fdc0623867bedc"
+checksum = "5252b3d2648e5eedbc1a6f501e3c795e07025c1e93bbf8bbdd6eef7f447a6d54"
 dependencies = [
+ "find-msvc-tools",
  "jobserver",
  "libc",
  "shlex",
@@ -225,9 +226,9 @@ dependencies = [
 
 [[package]]
 name = "downcast-rs"
-version = "2.0.1"
+version = "2.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ea8a8b81cacc08888170eef4d13b775126db426d0b348bee9d18c2c1eaf123cf"
+checksum = "117240f60069e65410b3ae1bb213295bd828f707b5bec6596a1afc8793ce0cbc"
 
 [[package]]
 name = "either"
@@ -278,6 +279,12 @@ dependencies = [
  "log",
 ]
 
+[[package]]
+name = "find-msvc-tools"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fd99930f64d146689264c637b5af2f0233a933bef0d8570e2526bf9e083192d"
+
 [[package]]
 name = "form_urlencoded"
 version = "1.2.2"
@@ -463,9 +470,9 @@ dependencies = [
 
 [[package]]
 name = "log"
-version = "0.4.27"
+version = "0.4.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13dc2df351e3202783a1fe0d44375f7295ffb4049267b0f3018346dc122a1d94"
+checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
 
 [[package]]
 name = "memchr"
@@ -485,7 +492,7 @@ dependencies = [
 [[package]]
 name = "mmtk"
 version = "0.31.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=6eb1328bfce34a7e0fc4b84fd0b65a849b083e0e#6eb1328bfce34a7e0fc4b84fd0b65a849b083e0e"
+source = "git+https://github.com/mmtk/mmtk-core.git?rev=ef153615d115edf196c0df2029e4340468276372#ef153615d115edf196c0df2029e4340468276372"
 dependencies = [
  "atomic",
  "atomic-traits",
@@ -524,7 +531,7 @@ dependencies = [
 [[package]]
 name = "mmtk-macros"
 version = "0.31.0"
-source = "git+https://github.com/mmtk/mmtk-core.git?rev=6eb1328bfce34a7e0fc4b84fd0b65a849b083e0e#6eb1328bfce34a7e0fc4b84fd0b65a849b083e0e"
+source = "git+https://github.com/mmtk/mmtk-core.git?rev=ef153615d115edf196c0df2029e4340468276372#ef153615d115edf196c0df2029e4340468276372"
 dependencies = [
  "proc-macro-error",
  "proc-macro2",
@@ -866,9 +873,9 @@ checksum = "5c1cb5db39152898a79168971543b1cb5020dff7fe43c8dc468b0885f5e29df5"
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.18"
+version = "1.0.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
+checksum = "f63a545481291138910575129486daeaf8ac54aee4387fe7906919f7830c7d9d"
 
 [[package]]
 name = "unicode-joining-type"
@@ -923,11 +930,20 @@ checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
 [[package]]
 name = "wasi"
-version = "0.14.2+wasi-0.2.4"
+version = "0.14.5+wasi-0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4494f6290a82f5fe584817a676a34b9d6763e8d9d18204009fb31dceca98fd4"
+dependencies = [
+ "wasip2",
+]
+
+[[package]]
+name = "wasip2"
+version = "1.0.0+wasi-0.2.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9683f9a5a998d873c0d21fcbe3c083009670149a8fab228644b8bd36b2c48cb3"
+checksum = "03fa2761397e5bd52002cd7e73110c71af2109aca4e521a9f40473fe685b0a24"
 dependencies = [
- "wit-bindgen-rt",
+ "wit-bindgen",
 ]
 
 [[package]]
@@ -1159,10 +1175,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "271414315aff87387382ec3d271b52d7ae78726f5d44ac98b4f4030c91880486"
 
 [[package]]
-name = "wit-bindgen-rt"
-version = "0.39.0"
+name = "wit-bindgen"
+version = "0.45.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f42320e61fe2cfd34354ecb597f86f413484a798ba44a8ca1165c58d42da6c1"
-dependencies = [
- "bitflags",
-]
+checksum = "5c573471f125075647d03df72e026074b7203790d41351cd6edc96f46bcccd36"
diff --git a/mmtk/Cargo.toml b/mmtk/Cargo.toml
index 1b2940b..59e3fd0 100644
--- a/mmtk/Cargo.toml
+++ b/mmtk/Cargo.toml
@@ -12,7 +12,7 @@ edition = "2021"
 # Metadata for the Ruby repository
 [package.metadata.ci-repos.ruby]
 repo = "mmtk/ruby" # This is used by actions/checkout, so the format is "owner/repo", not URL.
-rev = "fe51e6277b4df810a90c4474f951ed0a263acea0"
+rev = "e4f5cb73824dd411c0cb1cf12aca42996f427da3"
 
 [lib]
 name = "mmtk_ruby"
@@ -37,7 +37,7 @@ features = ["is_mmtk_object", "object_pinning", "sticky_immix_non_moving_nursery
 
 # Uncomment the following lines to use mmtk-core from the official repository.
 git = "https://github.com/mmtk/mmtk-core.git"
-rev = "6eb1328bfce34a7e0fc4b84fd0b65a849b083e0e"
+rev = "ef153615d115edf196c0df2029e4340468276372"
 
 # Uncomment the following line to use mmtk-core from a local repository.
 #path = "../../mmtk-core"