diff --git a/pyproject_buildrequires.py b/pyproject_buildrequires.py
index 51c6791..4fe44a7 100644
--- a/pyproject_buildrequires.py
+++ b/pyproject_buildrequires.py
@@ -195,7 +195,8 @@ def main(argv):
         exit(1)
 
     freeze_output = subprocess.run(
-        ['pip', 'freeze', '--all'],
+        [sys.executable, '-I', '-m', 'pip', 'freeze', '--all'],
+        encoding='utf-8',
         stdout=subprocess.PIPE,
         check=True,
     ).stdout