diff --git a/kitty/shell_integration.py b/kitty/shell_integration.py
index 8f94065b3..f8773436a 100644
--- a/kitty/shell_integration.py
+++ b/kitty/shell_integration.py
@@ -65,15 +65,12 @@ def setup_fish_integration(env: Dict[str, str]) -> None:
 
 def setup_fish_env(env: Dict[str, str]) -> None:
     val = env.get('XDG_DATA_DIRS')
-    if val is None:
+    env['KITTY_FISH_XDG_DATA_DIR'] = shell_integration_dir
+    if not val:
         env['XDG_DATA_DIRS'] = shell_integration_dir
-    elif not val:
-        env['XDG_DATA_DIRS'] = shell_integration_dir
-        env['KITTY_FISH_XDG_DATA_DIRS'] = ''
     else:
         dirs = list(filter(None, val.split(os.pathsep)))
         dirs.insert(0, shell_integration_dir)
-        env['KITTY_FISH_XDG_DATA_DIRS'] = val
         env['XDG_DATA_DIRS'] = os.pathsep.join(dirs)
 
 
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 6a1b4866d..37a2b132d 100644
--- a/shell-integration/fish/vendor_conf.d/kitty-shell-integration.fish
+++ b/shell-integration/fish/vendor_conf.d/kitty-shell-integration.fish
@@ -2,14 +2,21 @@
 
 function _ksi_main
     test -z "$KITTY_SHELL_INTEGRATION" && return
-    if set -q KITTY_FISH_XDG_DATA_DIRS
-        set --global --export XDG_DATA_DIRS "$KITTY_FISH_XDG_DATA_DIRS"
-    else
-        set --erase XDG_DATA_DIRS
+    if set -q XDG_DATA_DIRS
+        set --global --export --path XDG_DATA_DIRS "$XDG_DATA_DIRS"
+        if set -q KITTY_FISH_XDG_DATA_DIR
+            if set -l index (contains -i "$KITTY_FISH_XDG_DATA_DIR" $XDG_DATA_DIRS)
+                set --erase --global XDG_DATA_DIRS[$index]
+                test -z "$XDG_DATA_DIRS" && set --erase --global XDG_DATA_DIRS
+            end
+        end
+        if set -q XDG_DATA_DIRS
+            set --global --export --unpath XDG_DATA_DIRS "$XDG_DATA_DIRS"
+        end
     end
     set --local _ksi (string split " " -- "$KITTY_SHELL_INTEGRATION")
     set --erase KITTY_SHELL_INTEGRATION
-    set --erase KITTY_FISH_XDG_DATA_DIRS
+    set --erase KITTY_FISH_XDG_DATA_DIR
 
     function _ksi_osc
         printf "\e]%s\a" "$argv[1]"