diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index ca296bc..2d8757b 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -63,7 +63,7 @@ jobs:
         uses: actions/checkout@v3
 
       - name: ${{ matrix.trimming }} ${{ matrix.memory-management }} build
-        run: v -shared ${{ matrix.trimming }} ${{ matrix.memory-management }} .
+        run: v -shared -prod ${{ matrix.trimming }} ${{ matrix.memory-management }} .
 
   tests:
     needs: simple-build
diff --git a/src/register_service.v b/src/register_service.v
index 7470731..ac9a242 100644
--- a/src/register_service.v
+++ b/src/register_service.v
@@ -26,7 +26,7 @@ struct Factory {
 	can_instantiate fn () bool [required]
 	build           fn () !    [required]
 mut:
-	instantiated bool = false
+	instantiated bool
 }
 
 [inline]