diff --git a/.github/workflows/ci.linux.compiler.yml b/.github/workflows/ci.linux.compiler.yml
index dc4d0b13..cf895eed 100644
--- a/.github/workflows/ci.linux.compiler.yml
+++ b/.github/workflows/ci.linux.compiler.yml
@@ -51,8 +51,9 @@ jobs:
           name: output850
       - name: test
         run: |
-          # tar -x --use-compress-program=zstdmt -f output850.tzs
+          tar -x --use-compress-program=zstdmt -f output850.tzs
           ls -R
+          cd build/output
           ctest --timeout 3600 -V
 
   gcc921: