diff --git a/aider/io.py b/aider/io.py
index 1d275716e..ff3cab386 100644
--- a/aider/io.py
+++ b/aider/io.py
@@ -100,6 +100,7 @@ class InputOutput:
         user_input_color="blue",
         tool_output_color=None,
         tool_error_color="red",
+        encoding="utf-8",
     ):
         no_color = os.environ.get("NO_COLOR")
         if no_color is not None and no_color != "":
@@ -124,6 +125,8 @@ class InputOutput:
         else:
             self.chat_history_file = None
 
+        self.encoding = encoding
+
         if pretty:
             self.console = Console()
         else:
@@ -132,6 +135,14 @@ class InputOutput:
         current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
         self.append_chat_history(f"\n# aider chat started at {current_time}\n\n")
 
+    def read_text(self, filename):
+        try:
+            with open(filename, "r", encoding=self.encoding) as f:
+                return f.read()
+        except (FileNotFoundError, UnicodeError) as e:
+            self.tool_error(str(e))
+            return None
+
     def get_input(self, root, rel_fnames, addable_rel_fnames, commands):
         if self.pretty:
             style = dict(style=self.user_input_color) if self.user_input_color else dict()
diff --git a/aider/main.py b/aider/main.py
index decf1514f..cb2039351 100644
--- a/aider/main.py
+++ b/aider/main.py
@@ -185,6 +185,11 @@ def main(args=None, input=None, output=None):
         dest="dirty_commits",
         help="Disable commits when repo is found dirty",
     )
+    parser.add_argument(
+        "--encoding",
+        default="utf-8",
+        help="Specify the encoding to use when reading files (default: utf-8)",
+    )
     parser.add_argument(
         "--openai-api-key",
         metavar="OPENAI_API_KEY",