diff --git a/packages/ash/assembly/__tests__/jsonfs.spec.ts b/packages/ash/assembly/__tests__/jsonfs.spec.ts
index 45525e7..5e39ba2 100644
--- a/packages/ash/assembly/__tests__/jsonfs.spec.ts
+++ b/packages/ash/assembly/__tests__/jsonfs.spec.ts
@@ -8,6 +8,7 @@ describe("fs from JSON", (): void => {
 
     beforeEach(() => {
         fs.fs = new FileSystem();
+        fs.fs.init();
     });
 
 
diff --git a/packages/assemblyscript/assembly/wasa/mock/fs/index.ts b/packages/assemblyscript/assembly/wasa/mock/fs/index.ts
index 83f18dd..4f320a2 100644
--- a/packages/assemblyscript/assembly/wasa/mock/fs/index.ts
+++ b/packages/assemblyscript/assembly/wasa/mock/fs/index.ts
@@ -20,6 +20,7 @@ export class fs {
     static get fs(): FileSystem {
         if (!fs.initialized) {
             fs._fs.init();
+            fs.initialized = true;
         }
         return fs._fs;
     }