diff --git a/frontend/src/components/layout/SaveProjectModal.tsx b/frontend/src/components/layout/SaveProjectModal.tsx
index 4d0b0730..4ffb9c5d 100644
--- a/frontend/src/components/layout/SaveProjectModal.tsx
+++ b/frontend/src/components/layout/SaveProjectModal.tsx
@@ -58,15 +58,19 @@ export const SaveProjectModal: React.FC<SaveProjectModalProps> = ({ onClose }) =
       wires_json: JSON.stringify(wires),
     };
 
+    const UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+    const isValidUpdate = isUpdate && currentProject && UUID_RE.test(currentProject.id);
+
     try {
       let saved;
-      if (isUpdate && currentProject) {
-        saved = await updateProject(currentProject.id, payload);
+      if (isValidUpdate) {
+        saved = await updateProject(currentProject!.id, payload);
         trackSaveProject();
       } else {
         saved = await createProject(payload);
         trackCreateProject();
       }
+
       setCurrentProject({
         id: saved.id,
         slug: saved.slug,
diff --git a/frontend/src/pages/ProjectByIdPage.tsx b/frontend/src/pages/ProjectByIdPage.tsx
index 5c32cc4d..a6f69e5a 100644
--- a/frontend/src/pages/ProjectByIdPage.tsx
+++ b/frontend/src/pages/ProjectByIdPage.tsx
@@ -19,6 +19,7 @@ export const ProjectByIdPage: React.FC = () => {
   const loadFiles = useEditorStore((s) => s.loadFiles);
   const { setComponents, setWires, setBoardType } = useSimulatorStore();
   const setCurrentProject = useProjectStore((s) => s.setCurrentProject);
+  const clearCurrentProject = useProjectStore((s) => s.clearCurrentProject);
   const currentProject = useProjectStore((s) => s.currentProject);
   const [ready, setReady] = useState(false);
   const [error, setError] = useState('');
@@ -56,6 +57,7 @@ export const ProjectByIdPage: React.FC = () => {
         if (s === 404) setError('Project not found.');
         else if (s === 403) setError('This project is private.');
         else setError('Failed to load project.');
+        clearCurrentProject();
       });
   }, [id]);