diff --git a/.ci.sh b/.ci.sh
index b75f815c..e0171f18 100755
--- a/.ci.sh
+++ b/.ci.sh
@@ -39,7 +39,7 @@ if [[ ${RUNNER_OS} = macOS ]]; then
     latest_brew_python3_bin="$(ls -1d /usr/local/Cellar/python/3.*/bin | sort -n | tail -n1)"
     export PATH="${latest_brew_python3_bin}${PATH:+:}${PATH}"
 elif [[ ${RUNNER_OS} = Linux ]]; then
-    export PATH="/usr/lib/llvm-18/bin:${PATH}"
+    export PATH="/usr/lib/llvm-19/bin:${PATH}"
 else
     echo "Unsupported RUNNER_OS \"${RUNNER_OS}\"." >&2
     exit 1
diff --git a/.github/workflows/fuzzing.yml b/.github/workflows/fuzzing.yml
index ee3cb960..fc8d7595 100644
--- a/.github/workflows/fuzzing.yml
+++ b/.github/workflows/fuzzing.yml
@@ -46,18 +46,18 @@ jobs:
     steps:
     - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938  # v4.2.0
 
-    - name: Install Clang 18
+    - name: Install Clang 19
       run: |-
         set -x
         source /etc/os-release
         wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-        sudo add-apt-repository "deb https://apt.llvm.org/${UBUNTU_CODENAME}/ llvm-toolchain-${UBUNTU_CODENAME}-18 main"
+        sudo add-apt-repository "deb https://apt.llvm.org/${UBUNTU_CODENAME}/ llvm-toolchain-${UBUNTU_CODENAME}-19 main"
         sudo apt-get update  # due to new repository
         sudo apt-get install --yes --no-install-recommends -V \
-            clang-18 \
-            libclang-rt-18-dev \
-            llvm-18
-        echo /usr/lib/llvm-18/bin >>"${GITHUB_PATH}"
+            clang-19 \
+            libclang-rt-19-dev \
+            llvm-19
+        echo /usr/lib/llvm-19/bin >>"${GITHUB_PATH}"
 
     - name: Build Expat fuzzers
       run: |
diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index a492f1e0..2b533fb4 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -120,12 +120,12 @@ jobs:
         set -x
         source /etc/os-release
         wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
-        sudo add-apt-repository "deb https://apt.llvm.org/${UBUNTU_CODENAME}/ llvm-toolchain-${UBUNTU_CODENAME}-18 main"
+        sudo add-apt-repository "deb https://apt.llvm.org/${UBUNTU_CODENAME}/ llvm-toolchain-${UBUNTU_CODENAME}-19 main"
         sudo apt-get update  # due to new repository
-        # NOTE: Please note the version-specific ${PATH} extension for Clang adding /usr/lib/llvm-18/bin in .ci.sh
+        # NOTE: Please note the version-specific ${PATH} extension for Clang adding /usr/lib/llvm-19/bin in .ci.sh
         sudo apt-get install --yes --no-install-recommends -V \
-            clang-18 \
-            libclang-rt-18-dev
+            clang-19 \
+            libclang-rt-19-dev
     - name: Install build dependencies (common)
       run: |-
         sudo apt-get install --yes --no-install-recommends -V \