diff --git a/montepy/input_parser/input_file.py b/montepy/input_parser/input_file.py
index 00c60952..461306aa 100644
--- a/montepy/input_parser/input_file.py
+++ b/montepy/input_parser/input_file.py
@@ -79,7 +79,7 @@ def open(self, mode, encoding="ascii"):
         :type encoding: str
         :returns: self
         """
-        self._fh = open(self.path, mode, encoding="ascii")
+        self._fh = open(self.path, mode, encoding=encoding)
         return self
 
     def __enter__(self):
diff --git a/montepy/mcnp_problem.py b/montepy/mcnp_problem.py
index 802b8d5d..9984a2d6 100644
--- a/montepy/mcnp_problem.py
+++ b/montepy/mcnp_problem.py
@@ -261,7 +261,7 @@ def parse_input(self, check_input=False, encoding="ascii"):
         try:
             for i, input in enumerate(
                 input_syntax_reader.read_input_syntax(
-                    self._input_file, self.mcnp_version
+                    self._input_file, self.mcnp_version, encoding=encoding
                 )
             ):
                 self._original_inputs.append(input)