diff --git a/tests/filter-control-sequences.fish b/tests/filter-control-sequences.fish
new file mode 100755
index 000000000..6797f4a22
--- /dev/null
+++ b/tests/filter-control-sequences.fish
@@ -0,0 +1,17 @@
+#!/usr/bin/fish
+# Remove the sorts of escape sequences interactive fish prints.
+
+# First the enable sequences
+set -l escapes "\e\[\?2004h"\
+"\e\[>4;1m"\
+"\e\[>5u"\
+"\e="\
+# or
+"|"\
+# the disable sequences
+"\e\[\?2004l"\
+"\e\[>4;0m"\
+"\e\[<1u"\
+"\e>"
+
+cat | string replace -ra -- $escapes ''
diff --git a/tests/filter-control-sequences.sh b/tests/filter-control-sequences.sh
deleted file mode 100755
index ea7b04a61..000000000
--- a/tests/filter-control-sequences.sh
+++ /dev/null
@@ -1,14 +0,0 @@
-#!/bin/sh
-
-escape=$(printf '\033')
-
-"$1" -c 'cat | string replace -ra $argv[1] ""' -- "\
-""$escape\[\?2004h""\
-""$escape\[>4;1m""\
-""$escape\[>5u""\
-""$escape=""\
-""|""\
-""$escape\[\?2004l""\
-""$escape\[>4;0m""\
-""$escape\[<1u""\
-""$escape>"
diff --git a/tests/test.fish b/tests/test.fish
index ec3b49916..eac2b8eaf 100644
--- a/tests/test.fish
+++ b/tests/test.fish
@@ -42,7 +42,7 @@ if set -q files_to_test[1]
         --progress $force_color \
         -s fish=../test/root/bin/fish \
         -s fish_test_helper=../test/root/bin/fish_test_helper \
-        -s filter-control-sequences='../tests/filter-control-sequences.sh ../test/root/bin/fish' \
+        -s filter-control-sequences='../test/root/bin/fish ../tests/filter-control-sequences.fish' \
         $files_to_test
 
     set -l littlecheck_status $status