diff --git a/kitty/child.py b/kitty/child.py
index 13fcaf2b8..7f568cab8 100644
--- a/kitty/child.py
+++ b/kitty/child.py
@@ -229,9 +229,8 @@ class Child:
                 env['TERMINFO'] = tdir
             opts = fast_data_types.get_options()
             if opts.shell_integration != 'disabled':
-                from .shell_integration import get_supported_shell_name
-                if get_supported_shell_name(self.argv[0]):
-                    env['KITTY_SHELL_INTEGRATION'] = opts.shell_integration
+                from .shell_integration import modify_shell_environ
+                modify_shell_environ(self.argv[0], opts, env)
             env = {k: v for k, v in env.items() if v is not DELETE_ENV_VAR}
         return env
 
diff --git a/kitty/shell_integration.py b/kitty/shell_integration.py
index 8ca8826b1..8efb85690 100644
--- a/kitty/shell_integration.py
+++ b/kitty/shell_integration.py
@@ -60,15 +60,21 @@ def setup_bash_integration(env: Dict[str, str]) -> None:
 
 
 def setup_fish_integration(env: Dict[str, str]) -> None:
-    if 'XDG_DATA_DIRS' in env:
-        val = env.get('XDG_DATA_DIRS', '')
-        dirs = list(filter(None, val.split(os.pathsep)))
+    pass  # this is handled in the fish env modifier
+
+
+def setup_fish_env(env: Dict[str, str]) -> None:
+    val = env.get('XDG_DATA_DIRS')
+    if val is None:
+        env['XDG_DATA_DIRS'] = shell_integration_dir
+    elif not val:
+        env['XDG_DATA_DIRS'] = shell_integration_dir
+        env['KITTY_FISH_XDG_DATA_DIRS'] = ''
     else:
-        val = os.environ.get('XDG_DATA_DIRS', '')
         dirs = list(filter(None, val.split(os.pathsep)))
-    if shell_integration_dir not in dirs:
         dirs.insert(0, shell_integration_dir)
-    env['XDG_DATA_DIRS'] = os.pathsep.join(dirs)
+        env['KITTY_FISH_XDG_DATA_DIRS'] = val
+        env['XDG_DATA_DIRS'] = os.pathsep.join(dirs)
 
 
 SUPPORTED_SHELLS = {
@@ -76,6 +82,9 @@ SUPPORTED_SHELLS = {
     'bash': setup_bash_integration,
     'fish': setup_fish_integration,
 }
+ENV_MODIFIERS = {
+    'fish': setup_fish_env
+}
 
 
 def get_supported_shell_name(path: str) -> Optional[str]:
@@ -85,10 +94,16 @@ def get_supported_shell_name(path: str) -> Optional[str]:
     return None
 
 
-def setup_shell_integration(opts: Options, env: Dict[str, str]) -> bool:
+def shell_integration_allows_rc_modification(opts: Options) -> bool:
     q = set(opts.shell_integration.split())
     if q & {'disabled', 'no-rc'}:
         return False
+    return True
+
+
+def setup_shell_integration(opts: Options, env: Dict[str, str]) -> bool:
+    if not shell_integration_allows_rc_modification(opts):
+        return False
     shell = get_supported_shell_name(resolved_shell(opts)[0])
     if shell is None:
         return False
@@ -101,3 +116,16 @@ def setup_shell_integration(opts: Options, env: Dict[str, str]) -> bool:
         log_error(f'Failed to setup shell integration for: {shell}')
         return False
     return True
+
+
+def modify_shell_environ(argv0: str, opts: Options, env: Dict[str, str]) -> bool:
+    if not shell_integration_allows_rc_modification(opts):
+        return False
+    shell = get_supported_shell_name(argv0)
+    if shell is None:
+        return False
+    f = ENV_MODIFIERS.get(shell)
+    if f is not None:
+        f(env)
+    env['KITTY_SHELL_INTEGRATION'] = opts.shell_integration
+    return True
diff --git a/shell-integration/fish/vendor_conf.d/kitty-shell-integration.fish b/shell-integration/fish/vendor_conf.d/kitty-shell-integration.fish
index 0891f23e6..7d9f0f2b3 100644
--- a/shell-integration/fish/vendor_conf.d/kitty-shell-integration.fish
+++ b/shell-integration/fish/vendor_conf.d/kitty-shell-integration.fish
@@ -2,8 +2,14 @@
 
 function _ksi_main
     test -z "$KITTY_SHELL_INTEGRATION" && return
+    if set -q KITTY_FISH_XDG_DATA_DIRS
+        set --export XDG_DATA_DIRS "$KITTY_FISH_XDG_DATA_DIRS"
+    else
+        set --erase XDG_DATA_DIRS
+    end
     set --local _ksi (string split " " -- "$KITTY_SHELL_INTEGRATION")
     set --erase KITTY_SHELL_INTEGRATION
+    set --erase KITTY_FISH_XDG_DATA_DIRS
 
     function _ksi_osc
         printf "\e]%s\a" "$argv[1]"