diff --git a/harp/schema.py b/harp/schema.py
index 7abcdba..aa5d5e9 100644
--- a/harp/schema.py
+++ b/harp/schema.py
@@ -9,7 +9,7 @@
 
 def _read_common_registers() -> Registers:
     file = resources.files(__package__) / "common.yml"
-    with file.open("rt") as fileIO:
+    with file.open("r") as fileIO:
         return parse_yaml_raw_as(Registers, fileIO.read())