diff --git a/nanocode.py b/nanocode.py
index bbe0bf57..047237b6 100755
--- a/nanocode.py
+++ b/nanocode.py
@@ -22,7 +22,8 @@
 
 
 def read(args):
-    lines = open(args["path"]).readlines()
+    with open(args["path"], encoding="utf-8", errors="replace") as f:
+        lines = f.readlines()
     offset = args.get("offset", 0)
     limit = args.get("limit", len(lines))
     selected = lines[offset : offset + limit]
@@ -36,7 +37,8 @@ def write(args):
 
 
 def edit(args):
-    text = open(args["path"]).read()
+    with open(args["path"], encoding="utf-8") as f:
+        text = f.read()
     old, new = args["old"], args["new"]
     if old not in text:
         return "error: old_string not found"
@@ -67,7 +69,7 @@ def grep(args):
     hits = []
     for filepath in globlib.glob(args.get("path", ".") + "/**", recursive=True):
         try:
-            for line_num, line in enumerate(open(filepath), 1):
+            for line_num, line in enumerate(open(filepath, encoding="utf-8", errors="replace"), 1):
                 if pattern.search(line):
                     hits.append(f"{filepath}:{line_num}:{line.rstrip()}")
         except Exception: