diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index af2f2e7..395cc84 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -94,6 +94,9 @@ jobs:
         if: matrix.type == 'ghplugin'
         run: |
           set -e
+          # The SDK's Makefile archives with llvm-ar, which the clang package does
+          # not pull in on the runner image.
+          sudo apt-get install -y llvm
           git clone --depth 1 https://github.com/GoldHEN/GoldHEN_Plugins_SDK.git /tmp/goldhen-sdk
           make -C /tmp/goldhen-sdk install
           # 'make install' ships the headers and libGoldHEN_Hook.a but leaves crtprx.o