diff --git a/app/helper.py b/app/helper.py
index d328c50..0405c86 100644
--- a/app/helper.py
+++ b/app/helper.py
@@ -84,9 +84,9 @@ class PipenvOperation(object):
     def install(path=".", package_name=None):
         pip_install_options = "PIP_INSTALL_OPTION=\"-- --jobs=6\""
         if package_name:
-            command = f"{pip_install_options} pipenv install {package_name}"
+            command = [pip_install_options, "pipenv", "install", package_name]
         else:
-            command = f"{pip_install_options} pipenv install"
+            command = [pip_install_options, "pipenv", "install"]
         try:
             output = subprocess.check_output(command.split(), cwd=path)
         except subprocess.CalledProcessError as e: