diff --git a/worthless/installer.py b/worthless/installer.py
index 57c5cbf..a417f7e 100644
--- a/worthless/installer.py
+++ b/worthless/installer.py
@@ -413,8 +413,11 @@ class Installer:
             archive = Path(archive).resolve()
         if not archive.exists():
             raise FileNotFoundError(f"'{archive}' not found")
-        print(f'-o"{str(self._gamedir)}"')
-        proc = await asyncio.create_subprocess_shell(f"7z x {str(archive)} -o'{str(self._gamedir)}'")
+        game_dir_str = str(self._gamedir)
+        if not game_dir_str.endswith("/"):
+            game_dir_str += "/"
+        print(f'-o"{game_dir_str}"')
+        proc = await asyncio.create_subprocess_shell(f'7z x {str(archive)} -o"{game_dir_str}"')
         await proc.wait()
         if proc.returncode != 0:
             raise RuntimeError("Extracting failed")