diff --git a/shell-integration/kitty.fish b/shell-integration/kitty.fish
index 6861abd5b..34738c7f8 100644
--- a/shell-integration/kitty.fish
+++ b/shell-integration/kitty.fish
@@ -60,7 +60,7 @@ function _ksi_main
 
         function _ksi_end_prompt
             set --local cmd_status "$status"
-            set --local op (_ksi_original_fish_prompt)  # trim trailing newlines to mimic fish behavior
+            set --local op (_ksi_original_fish_prompt | string collect)  # trim trailing newlines to mimic fish behavior
             printf "%s" "$op"
             set --global _ksi_prompt_state "prompt_end"
             _ksi_mark "B"