diff --git a/gen-go-code.py b/gen-go-code.py
index c784d0961..a261bb0b8 100755
--- a/gen-go-code.py
+++ b/gen-go-code.py
@@ -4,6 +4,7 @@
 import bz2
 import io
 import json
+import kitty.constants as kc
 import os
 import re
 import struct
@@ -13,27 +14,24 @@ import tarfile
 from contextlib import contextmanager, suppress
 from functools import lru_cache
 from itertools import chain
-from typing import Any, BinaryIO, Dict, Iterator, List, Optional, Sequence, Set, TextIO, Tuple, Union
-
-import kitty.constants as kc
 from kittens.tui.operations import Mode
 from kittens.tui.spinners import spinners
 from kitty.cli import (
-    CompletionSpec,
-    GoOption,
-    go_options_for_seq,
-    parse_option_spec,
+    CompletionSpec, GoOption, go_options_for_seq, parse_option_spec,
     serialize_as_go_string,
 )
 from kitty.conf.generate import gen_go_code
 from kitty.conf.types import Definition
-from kitty.guess_mime_type import text_mimes
+from kitty.guess_mime_type import known_extensions, text_mimes
 from kitty.key_encoding import config_mod_map
 from kitty.key_names import character_key_name_aliases, functional_key_name_aliases
 from kitty.options.types import Options
 from kitty.rc.base import RemoteCommand, all_command_names, command_for_name
 from kitty.remote_control import global_options_spec
 from kitty.rgb import color_names
+from typing import (
+    Any, BinaryIO, Dict, Iterator, List, Optional, Sequence, Set, TextIO, Tuple, Union,
+)
 
 changed: List[str] = []
 
@@ -673,6 +671,10 @@ def generate_textual_mimetypes() -> str:
     for k in text_mimes:
         ans.append(f'  "{serialize_as_go_string(k)}": true,')
     ans.append('}')
+    ans.append('var KnownExtensions = map[string]string{')
+    for k, v in known_extensions.items():
+        ans.append(f'  ".{serialize_as_go_string(k)}": "{serialize_as_go_string(v)}",')
+    ans.append('}')
     return '\n'.join(ans)
 
 
diff --git a/tools/utils/mimetypes.go b/tools/utils/mimetypes.go
index b6d01d2f8..d1027bcca 100644
--- a/tools/utils/mimetypes.go
+++ b/tools/utils/mimetypes.go
@@ -11,6 +11,8 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+
+	"golang.org/x/sys/unix"
 )
 
 var _ = fmt.Print
@@ -52,6 +54,11 @@ var UserMimeMap = (&Once[map[string]string]{Run: func() map[string]string {
 	return ans
 }}).Get
 
+func is_rcfile(path string) bool {
+	name := filepath.Base(path)
+	return strings.HasSuffix(name, "rc") && !strings.Contains(name, ".")
+}
+
 func GuessMimeType(filename string) string {
 	ext := filepath.Ext(filename)
 	mime_with_parameters := UserMimeMap()[ext]
@@ -62,7 +69,14 @@ func GuessMimeType(filename string) string {
 		only_once.Do(set_builtins)
 		mime_with_parameters = builtin_types_map[ext]
 		if mime_with_parameters == "" {
-			mime_with_parameters = builtin_types_map[strings.ToLower(ext)]
+			lext := strings.ToLower(ext)
+			mime_with_parameters = builtin_types_map[lext]
+			if mime_with_parameters == "" {
+				mime_with_parameters = KnownExtensions[lext]
+			}
+			if mime_with_parameters == "" && is_rcfile(filename) {
+				mime_with_parameters = "text/plain"
+			}
 			if mime_with_parameters == "" {
 				return ""
 			}
@@ -74,3 +88,24 @@ func GuessMimeType(filename string) string {
 	}
 	return ans
 }
+
+func GuessMimeTypeWithFileSystemAccess(filename string) string {
+	is_dir, is_exe := false, false
+	s, err := os.Stat(filename)
+	if err == nil {
+		is_dir = s.IsDir()
+		if !is_dir && s.Mode().Perm()&0o111 != 0 && unix.Access(filename, unix.X_OK) == nil {
+			is_exe = true
+		}
+	}
+	if is_dir {
+		return "inode/directory"
+	}
+	mt := GuessMimeType(filename)
+	if mt == "" {
+		if is_exe {
+			mt = "inode/executable"
+		}
+	}
+	return mt
+}