diff --git a/installer.py b/installer.py
index 83221fc7a..f8bb39c2c 100644
--- a/installer.py
+++ b/installer.py
@@ -410,9 +410,9 @@ def check_torch():
             rocm_ver = None
         if rocm_ver in {"5.7"}:
             # install torch nightly via torchvision to avoid wasting bandwidth when torchvision depends on torch from yesterday
-            torch_command = os.environ.get('TORCH_COMMAND', 'torch torchvision --pre --index-url https://download.pytorch.org/whl/nightly/rocm{rocm_ver}')
+            torch_command = os.environ.get('TORCH_COMMAND', f'torch torchvision --pre --index-url https://download.pytorch.org/whl/nightly/rocm{rocm_ver}')
         elif rocm_ver in {"5.5", "5.6"}:
-            torch_command = os.environ.get('TORCH_COMMAND', 'torch torchvision --index-url https://download.pytorch.org/whl/nightly/rocm{rocm_ver}')
+            torch_command = os.environ.get('TORCH_COMMAND', f'torch torchvision --index-url https://download.pytorch.org/whl/nightly/rocm{rocm_ver}')
         else:
             # ROCm 5.5 is oldest for PyTorch 2.1
             torch_command = os.environ.get('TORCH_COMMAND', 'torch torchvision --index-url https://download.pytorch.org/whl/rocm5.5')