diff --git a/.github/workflows/ci.generate.ts b/.github/workflows/ci.generate.ts
index 9446a44b80..6fbe41778a 100755
--- a/.github/workflows/ci.generate.ts
+++ b/.github/workflows/ci.generate.ts
@@ -5,7 +5,7 @@ import * as yaml from "https://deno.land/std@0.173.0/encoding/yaml.ts";
 // Bump this number when you want to purge the cache.
 // Note: the tools/release/01_bump_crate_versions.ts script will update this version
 // automatically via regex, so ensure that this line maintains this format.
-const cacheVersion = 41;
+const cacheVersion = 42;
 
 const Runners = (() => {
   const ubuntuRunner = "ubuntu-22.04";
@@ -27,19 +27,21 @@ const Runners = (() => {
 const prCacheKeyPrefix =
   `${cacheVersion}-cargo-target-\${{ matrix.os }}-\${{ matrix.profile }}-\${{ matrix.job }}-`;
 
+// Note that you may need to add more version to the `apt-get remove` line below if you change this
+const llvmVersion = 16;
 const installPkgsCommand =
-  "sudo apt-get install --no-install-recommends debootstrap clang-15 lld-15 clang-tools-15 clang-format-15 clang-tidy-15";
+  `sudo apt-get install --no-install-recommends debootstrap clang-${llvmVersion} lld-${llvmVersion} clang-tools-${llvmVersion} clang-format-${llvmVersion} clang-tidy-${llvmVersion}`;
 const sysRootStep = {
   name: "Set up incremental LTO and sysroot build",
   run: `# Avoid running man-db triggers, which sometimes takes several minutes
 # to complete.
 sudo apt-get remove --purge -y man-db
 # Remove older clang before we install
-sudo apt-get remove 'clang-12*' 'clang-13*' 'clang-14*' 'llvm-12*' 'llvm-13*' 'llvm-14*' 'lld-12*' 'lld-13*' 'lld-14*'
+sudo apt-get remove 'clang-12*' 'clang-13*' 'clang-14*' 'clang-15*' 'llvm-12*' 'llvm-13*' 'llvm-14*' 'llvm-15*' 'lld-12*' 'lld-13*' 'lld-14*' 'lld-15*'
 
-# Install clang-15, lld-15, and debootstrap.
-echo "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-15 main" |
-  sudo dd of=/etc/apt/sources.list.d/llvm-toolchain-jammy-15.list
+# Install clang-XXX, lld-XXX, and debootstrap.
+echo "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-${llvmVersion} main" |
+  sudo dd of=/etc/apt/sources.list.d/llvm-toolchain-jammy-${llvmVersion}.list
 curl https://apt.llvm.org/llvm-snapshot.gpg.key |
   gpg --dearmor                                 |
 sudo dd of=/etc/apt/trusted.gpg.d/llvm-snapshot.gpg
@@ -78,8 +80,8 @@ CARGO_PROFILE_RELEASE_INCREMENTAL=false
 CARGO_PROFILE_RELEASE_LTO=false
 RUSTFLAGS<<__1
   -C linker-plugin-lto=true
-  -C linker=clang-15
-  -C link-arg=-fuse-ld=lld-15
+  -C linker=clang-${llvmVersion}
+  -C link-arg=-fuse-ld=lld-${llvmVersion}
   -C link-arg=--sysroot=/sysroot
   -C link-arg=-ldl
   -C link-arg=-Wl,--allow-shlib-undefined
@@ -90,8 +92,8 @@ RUSTFLAGS<<__1
 __1
 RUSTDOCFLAGS<<__1
   -C linker-plugin-lto=true
-  -C linker=clang-15
-  -C link-arg=-fuse-ld=lld-15
+  -C linker=clang-${llvmVersion}
+  -C link-arg=-fuse-ld=lld-${llvmVersion}
   -C link-arg=--sysroot=/sysroot
   -C link-arg=-ldl
   -C link-arg=-Wl,--allow-shlib-undefined
@@ -99,7 +101,7 @@ RUSTDOCFLAGS<<__1
   -C link-arg=-Wl,--thinlto-cache-policy,cache_size_bytes=700m
   \${{ env.RUSTFLAGS }}
 __1
-CC=clang-15
+CC=clang-${llvmVersion}
 CFLAGS=-flto=thin --sysroot=/sysroot
 __0`,
 };
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 39da436825..62ed56aa3b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -216,17 +216,17 @@ jobs:
           # to complete.
           sudo apt-get remove --purge -y man-db
           # Remove older clang before we install
-          sudo apt-get remove 'clang-12*' 'clang-13*' 'clang-14*' 'llvm-12*' 'llvm-13*' 'llvm-14*' 'lld-12*' 'lld-13*' 'lld-14*'
+          sudo apt-get remove 'clang-12*' 'clang-13*' 'clang-14*' 'clang-15*' 'llvm-12*' 'llvm-13*' 'llvm-14*' 'llvm-15*' 'lld-12*' 'lld-13*' 'lld-14*' 'lld-15*'
 
-          # Install clang-15, lld-15, and debootstrap.
-          echo "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-15 main" |
-            sudo dd of=/etc/apt/sources.list.d/llvm-toolchain-jammy-15.list
+          # Install clang-XXX, lld-XXX, and debootstrap.
+          echo "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-16 main" |
+            sudo dd of=/etc/apt/sources.list.d/llvm-toolchain-jammy-16.list
           curl https://apt.llvm.org/llvm-snapshot.gpg.key |
             gpg --dearmor                                 |
           sudo dd of=/etc/apt/trusted.gpg.d/llvm-snapshot.gpg
           sudo apt-get update
           # this was unreliable sometimes, so try again if it fails
-          sudo apt-get install --no-install-recommends debootstrap clang-15 lld-15 clang-tools-15 clang-format-15 clang-tidy-15 || echo 'Failed. Trying again.' && sudo apt-get clean && sudo apt-get update && sudo apt-get install --no-install-recommends debootstrap clang-15 lld-15 clang-tools-15 clang-format-15 clang-tidy-15
+          sudo apt-get install --no-install-recommends debootstrap clang-16 lld-16 clang-tools-16 clang-format-16 clang-tidy-16 || echo 'Failed. Trying again.' && sudo apt-get clean && sudo apt-get update && sudo apt-get install --no-install-recommends debootstrap clang-16 lld-16 clang-tools-16 clang-format-16 clang-tidy-16
           # Fix alternatives
           (yes '' | sudo update-alternatives --force --all) || true
 
@@ -259,8 +259,8 @@ jobs:
           CARGO_PROFILE_RELEASE_LTO=false
           RUSTFLAGS<<__1
             -C linker-plugin-lto=true
-            -C linker=clang-15
-            -C link-arg=-fuse-ld=lld-15
+            -C linker=clang-16
+            -C link-arg=-fuse-ld=lld-16
             -C link-arg=--sysroot=/sysroot
             -C link-arg=-ldl
             -C link-arg=-Wl,--allow-shlib-undefined
@@ -271,8 +271,8 @@ jobs:
           __1
           RUSTDOCFLAGS<<__1
             -C linker-plugin-lto=true
-            -C linker=clang-15
-            -C link-arg=-fuse-ld=lld-15
+            -C linker=clang-16
+            -C link-arg=-fuse-ld=lld-16
             -C link-arg=--sysroot=/sysroot
             -C link-arg=-ldl
             -C link-arg=-Wl,--allow-shlib-undefined
@@ -280,7 +280,7 @@ jobs:
             -C link-arg=-Wl,--thinlto-cache-policy,cache_size_bytes=700m
             ${{ env.RUSTFLAGS }}
           __1
-          CC=clang-15
+          CC=clang-16
           CFLAGS=-flto=thin --sysroot=/sysroot
           __0
       - name: Log versions
@@ -304,8 +304,8 @@ jobs:
           path: |-
             ~/.cargo/registry/index
             ~/.cargo/registry/cache
-          key: '41-cargo-home-${{ matrix.os }}-${{ hashFiles(''Cargo.lock'') }}'
-          restore-keys: '41-cargo-home-${{ matrix.os }}'
+          key: '42-cargo-home-${{ matrix.os }}-${{ hashFiles(''Cargo.lock'') }}'
+          restore-keys: '42-cargo-home-${{ matrix.os }}'
         if: '!(github.event_name == ''pull_request'' && matrix.skip_pr)'
       - name: Restore cache build output (PR)
         uses: actions/cache/restore@v3
@@ -317,7 +317,7 @@ jobs:
             !./target/*/*.zip
             !./target/*/*.tar.gz
           key: never_saved
-          restore-keys: '41-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ matrix.job }}-'
+          restore-keys: '42-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ matrix.job }}-'
       - name: Apply and update mtime cache
         if: '!(github.event_name == ''pull_request'' && matrix.skip_pr) && (!startsWith(github.ref, ''refs/tags/''))'
         uses: ./.github/mtime_cache
@@ -605,7 +605,7 @@ jobs:
             !./target/*/gn_out
             !./target/*/*.zip
             !./target/*/*.tar.gz
-          key: '41-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ matrix.job }}-${{ github.sha }}'
+          key: '42-cargo-target-${{ matrix.os }}-${{ matrix.profile }}-${{ matrix.job }}-${{ github.sha }}'
   publish-canary:
     name: publish canary
     runs-on: ubuntu-22.04
diff --git a/Cargo.lock b/Cargo.lock
index e23d71f8a5..c3fd56f960 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2904,9 +2904,9 @@ dependencies = [
 
 [[package]]
 name = "libffi-sys"
-version = "2.2.1"
+version = "2.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc65067b78c0fc069771e8b9a9e02df71e08858bec92c1f101377c67b9dca7c7"
+checksum = "f36115160c57e8529781b4183c2bb51fdc1f6d6d1ed345591d84be7703befb3c"
 dependencies = [
  "cc",
 ]
diff --git a/ext/ffi/Cargo.toml b/ext/ffi/Cargo.toml
index 3a1c9d7a33..2b2f0b657f 100644
--- a/ext/ffi/Cargo.toml
+++ b/ext/ffi/Cargo.toml
@@ -18,7 +18,7 @@ deno_core.workspace = true
 dlopen.workspace = true
 dynasmrt = "1.2.3"
 libffi = "=3.2.0"
-libffi-sys = "=2.2.1"
+libffi-sys = "=2.3.0"
 serde.workspace = true
 serde-value = "0.7"
 serde_json = "1.0"
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 434cca4575..0538cafabc 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "1.68.2"
+channel = "1.70"
 components = ["rustfmt", "clippy"]