diff --git a/.github/workflows/compilers.yml b/.github/workflows/compilers.yml
index e9b5e882c2ae71..4a3a82d10e4c6d 100644
--- a/.github/workflows/compilers.yml
+++ b/.github/workflows/compilers.yml
@@ -261,7 +261,7 @@ jobs:
       - run: make test BTESTS=-j1
         env:
           RUBY_DEBUG_LOG: /tmp/log
-          RUBY_DEBUG_LOG_FILTER=pthread
+          RUBY_DEBUG_LOG_FILTER: pthread
           RUBY_ON_BUG='cat /tmp/log '
 
       - run: make install