diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2e018c3..f7e0a0f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -90,6 +90,8 @@
       run: |
         sudo apt-get update
         sudo apt-get install -y clang llvm
+    - name: Work around https://github.com/actions/runner-images/issues/9491
+      run: sudo sysctl vm.mmap_rnd_bits=28
     - run: scripts/run-tests.sh sanitizers
 
   valgrind-test: