diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index fce3eef2bd3ede..1ec7f18640faf7 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -114,12 +114,11 @@ jobs:
       - name: Build shared GC (${{ matrix.gc_name }})
         run: >
           mkdir ${{ matrix.shared_gc_dir }} &&
-          make shared-gc SHARED_GC=${{ matrix.gc_name }}
+          make shared-gc SHARED_GC=${{ matrix.gc_name }} MMTK_BUILD=release
         if: ${{ matrix.shared_gc }}
         env:
           RUBY_GC_LIBRARY: 'librubygc.${{ matrix.gc_name }}.so'
-          SHARED_GC: ${{ matrix.gc_name }}
-          MMTK_BUILD: 'release'
+
 
       - run: $SETARCH make