diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 32d6177c148..933d9b291e9 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -43,8 +43,8 @@ jobs:
       - name: Verify that we are in an environment with limited dev tools
         run: |
           set -x
-          for pattern in cmake g++ libssl-dev make pkgconf pkg-config; do
-            if dpkg-query --status -- "$pattern"; then
+          for package in cmake g++ libssl-dev make pkgconf pkg-config; do
+            if dpkg-query --status -- "$package"; then
               exit 1
             fi
           done
@@ -64,6 +64,9 @@ jobs:
           pattern='.*\b(-sys|cc|cmake|pkg-config|vcpkg)\b.*'
           ! GREP_COLORS='ms=30;48;5;214' grep --color=always -Ex -C 1000000 -e "$pattern" tree.txt
         continue-on-error: true
+      - name: Check for unrecognized *-sys dependencies
+        run: |
+          ! grep -qP '(?<!\blinux-raw)-sys\b' tree.txt
       - name: Wrap cc1 (and cc1plus if present) to record calls
         run: |
           cat >/usr/local/bin/wrapper1 <<'EOF'