diff --git a/common/params.py b/common/params.py
index d0a37cce1..2cfca3712 100644
--- a/common/params.py
+++ b/common/params.py
@@ -6,19 +6,14 @@ assert put_nonblocking
 
 if __name__ == "__main__":
   import sys
-  from common.params_pyx import keys # pylint: disable=no-name-in-module, import-error
 
   params = Params()
+  key = sys.argv[1]
+  assert params.check_key(key), f"unknown param: {key}"
+
   if len(sys.argv) == 3:
-    name = sys.argv[1]
     val = sys.argv[2]
-    assert name.encode("utf-8") in keys.keys(), f"unknown param: {name}"
-    print(f"SET: {name} = {val}")
-    params.put(name, val)
+    print(f"SET: {key} = {val}")
+    params.put(key, val)
   elif len(sys.argv) == 2:
-    name = sys.argv[1]
-    assert name.encode("utf-8") in keys.keys(), f"unknown param: {name}"
-    print(f"GET: {name} = {params.get(name)}")
-  else:
-    for k in keys.keys():
-      print(f"GET: {k} = {params.get(k)}")
+    print(f"GET: {key} = {params.get(key)}")