diff --git a/grafast/grafast/src/engine/OperationPlan.ts b/grafast/grafast/src/engine/OperationPlan.ts
index 15e258c78b..dde33becf9 100644
--- a/grafast/grafast/src/engine/OperationPlan.ts
+++ b/grafast/grafast/src/engine/OperationPlan.ts
@@ -2499,6 +2499,8 @@ export class OperationPlan {
           // OPTIMIZE: figure out under which circumstances it is safe to hoist here.
           // break;
           return;
+        } else if (step instanceof __FlagStep) {
+          break;
         } else {
           // Plans that rely on external state shouldn't be hoisted because
           // their results may change after a mutation, so the mutation should