diff --git a/tests/sandbox/js/ttkproxy.js b/tests/sandbox/js/ttkproxy.js
index d805d0f6..b62be65e 100644
--- a/tests/sandbox/js/ttkproxy.js
+++ b/tests/sandbox/js/ttkproxy.js
@@ -73,7 +73,7 @@ class TTkProxy {
     }
 
     async loadFile(fileUri,file){
-        this.pyodide.FS.writeFile(this.pyodide.FS.currentPath+file, await (await fetch(fileUri)).text());
+        this.pyodide.FS.writeFile(this.pyodide.FS.currentPath+'/'+file, await (await fetch(fileUri)).text());
     }
 
     readFile(file){
diff --git a/tests/sandbox/sandbox.NerdFont.html b/tests/sandbox/sandbox.NerdFont.html
index dced2e1b..8c1a4e93 100644
--- a/tests/sandbox/sandbox.NerdFont.html
+++ b/tests/sandbox/sandbox.NerdFont.html
@@ -147,7 +147,7 @@
         fileUri  = urlParams.get("fileUri")
         filePath = urlParams.get("filePath")
         if (fileUri != null){
-          ttkProxy.loadFile(fileUri, "test_file.py");
+          await ttkProxy.loadFile(fileUri, "test_file.py");
           loadFile("test_file.py")
         }else if (filePath != null){
           loadFile(filePath)
diff --git a/tests/sandbox/sandbox.base.html b/tests/sandbox/sandbox.base.html
index 9557835c..deeba8b7 100644
--- a/tests/sandbox/sandbox.base.html
+++ b/tests/sandbox/sandbox.base.html
@@ -157,7 +157,7 @@
         fileUri  = urlParams.get("fileUri")
         filePath = urlParams.get("filePath")
         if (fileUri != null){
-          ttkProxy.loadFile(fileUri, "test_file.py");
+          await ttkProxy.loadFile(fileUri, "test_file.py");
           loadFile("test_file.py")
         }else if (filePath != null){
           loadFile(filePath)