diff --git a/binfmt.py b/binfmt.py
index 7c536fc..fe8fea2 100644
--- a/binfmt.py
+++ b/binfmt.py
@@ -2,8 +2,8 @@
 
 import os
 import logging
-import subprocess
 
+from exec import run_root_cmd
 from utils import mount
 
 
@@ -63,7 +63,7 @@ def register(arch):
 
     # Register in binfmt_misc
     logging.info(f"Registering qemu binfmt ({arch})")
-    subprocess.run(["sh", "-c", 'echo "' + code + '" > ' + register + ' 2>/dev/null'])
+    run_root_cmd(["sh", "-c", f'echo "{code}" > {register} 2>/dev/null'])
     if not is_registered(arch):
         logging.debug(f'binfmt line: {code}')
         raise Exception(f'Failed to register qemu-user for {arch} with binfmt_misc, {binfmt}/{info["name"]} not found')
@@ -74,4 +74,4 @@ def unregister(arch):
     if not os.path.exists(binfmt_file):
         return
     logging.info(f"Unregistering qemu binfmt ({arch})")
-    subprocess.run(["sh", "-c", "echo -1 > " + binfmt_file])
+    run_root_cmd(["sh", "-c", f"echo -1 > {binfmt_file}"])