diff --git a/.github/workflows/linux.yml b/.github/workflows/linux.yml
index 6eeb6b697e..ccf171d932 100644
--- a/.github/workflows/linux.yml
+++ b/.github/workflows/linux.yml
@@ -55,6 +55,8 @@ env:
   RUSTLS_VERSION: 0.15.0
   # handled in renovate.json
   OPENLDAP_VERSION: 2.6.10
+  # renovate: datasource=github-tags depName=pizlonator/fil-c versioning=semver-partial registryUrl=https://github.com
+  FIL_C_VERSION: 0.674
 
 jobs:
   linux:
@@ -213,6 +215,15 @@ jobs:
           - name: '!ssl !http !smtp !imap'
             configure: --without-ssl --enable-debug --disable-http --disable-smtp --disable-imap --disable-unity
 
+          - name: 'Fil-C'
+            install_steps: filc
+            CC: /home/runner/filc/build/bin/filcc
+            generate: >-
+              -DBUILD_STATIC_LIBS=ON -DBUILD_SHARED_LIBS=OFF -DCMAKE_UNITY_BUILD=OFF
+              -DCURL_ENABLE_SSL=OFF -DCURL_USE_LIBPSL=OFF
+              -DCURL_ZLIB=OFF -DCURL_BROTLI=OFF -DCURL_ZSTD=OFF
+              -DUSE_NGHTTP2=OFF -DCURL_DISABLE_LDAP=ON -DUSE_LIBIDN2=OFF -DCURL_USE_LIBSSH2=OFF
+
           - name: 'clang-tidy'
             install_packages: clang-tidy libssl-dev libidn2-dev libssh2-1-dev libnghttp2-dev libldap-dev libkrb5-dev librtmp-dev libgnutls28-dev
             install_steps: skipall mbedtls rustls wolfssl-opensslextra
@@ -351,7 +362,7 @@ jobs:
             HOMEBREW_NO_AUTO_UPDATE=1 /home/linuxbrew/.linuxbrew/bin/brew install ${INSTALL_PACKAGES_BREW}
           fi
 
-      - name: 'install prereqs'
+      - name: 'install prereqs (i686)'
         if: ${{ contains(matrix.build.name, 'i686') }}
         run: |
           sudo rm -f /etc/apt/sources.list.d/microsoft-prod.list
@@ -363,7 +374,7 @@ jobs:
             libpsl-dev:i386 libbrotli-dev:i386 libzstd-dev:i386 \
             ${MATRIX_INSTALL_PACKAGES}
 
-      - name: 'install dependencies'
+      - name: 'install prereqs (alpine)'
         if: ${{ startsWith(matrix.build.container, 'alpine') }}
         run: |
           apk add --no-cache build-base autoconf automake libtool perl openssl-dev \
@@ -372,6 +383,16 @@ jobs:
             py3-impacket py3-asn1 py3-six py3-pycryptodomex \
             perl-time-hires openssh stunnel sudo git openssl
 
+      - name: 'install Fil-C'
+        if: ${{ contains(matrix.build.install_steps, 'filc') }}
+        run: |
+          cd /home/runner
+          curl --disable --fail --silent --show-error --connect-timeout 15 --max-time 120 --retry 6 --retry-connrefused \
+            --location "https://github.com/pizlonator/fil-c/releases/download/v${FIL_C_VERSION}/filc-${FIL_C_VERSION}-linux-x86_64.tar.xz" | tar -xJ
+          mv "filc-${FIL_C_VERSION}-linux-x86_64" filc
+          cd filc
+          ./setup.sh
+
       - name: 'cache libressl'
         if: ${{ contains(matrix.build.install_steps, 'libressl') }}
         uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
@@ -652,7 +673,7 @@ jobs:
           fi
 
       - name: 'single-use function check'
-        if: ${{ contains(matrix.build.configure, '--disable-unity') || contains(matrix.build.generate, '-DCMAKE_UNITY_BUILD=OFF') }}
+        if: ${{ (contains(matrix.build.configure, '--disable-unity') || contains(matrix.build.generate, '-DCMAKE_UNITY_BUILD=OFF')) && !contains(matrix.build.install_steps, 'filc') }}
         run: |
           git config --global --add safe.directory "*"
           if [ "${MATRIX_BUILD}" = 'cmake' ]; then