diff --git a/webapp/src/store/ProjectStore.spec.ts b/webapp/src/store/ProjectStore.spec.ts
index b323d3d..78cbddc 100644
--- a/webapp/src/store/ProjectStore.spec.ts
+++ b/webapp/src/store/ProjectStore.spec.ts
@@ -140,6 +140,37 @@ describe('ProjectStore', () => {
     });
   });
 
+  describe('updateTranslation', () => {
+    it('does not prefix source file with /', async () => {
+      const store = new ProjectStore(
+        {
+          getMessages: async () => [
+            {
+              defaultMessage: 'Click',
+              id: 'core.click',
+              params: [],
+            },
+          ],
+        },
+        {
+          getTranslations: async () => ({
+            en: {
+              'core.click': {
+                sourceFile: 'en.yml',
+                text: 'Click',
+              },
+            },
+          }),
+        },
+      );
+
+      await store.updateTranslation('sv', 'core.click', 'Klicka');
+
+      const actual = await store.getTranslations('sv');
+      expect(actual['core.click'].sourceFile).toEqual('sv.yml');
+    });
+  });
+
   it('gives full access to all languages', async () => {
     const msgAdapter = mockMsgAdapter();
     msgAdapter.getMessages.mockResolvedValue([
diff --git a/webapp/src/store/ProjectStore.ts b/webapp/src/store/ProjectStore.ts
index a7477b6..645ea16 100644
--- a/webapp/src/store/ProjectStore.ts
+++ b/webapp/src/store/ProjectStore.ts
@@ -100,6 +100,7 @@ export class ProjectStore {
       /^en\.(.+\.)*(ya?ml)$/g,
       `${lang}.$1$2`,
     );
-    return enSourceFileArr.join('/').concat(`/${langFileName}`);
+    enSourceFileArr.push(langFileName);
+    return enSourceFileArr.join('/');
   }
 }