diff --git a/pkgs/shells/fish/default.nix b/pkgs/shells/fish/default.nix
index b26695cab0e2..622521781c1b 100644
--- a/pkgs/shells/fish/default.nix
+++ b/pkgs/shells/fish/default.nix
@@ -134,7 +134,7 @@ let
 
   fish = stdenv.mkDerivation rec {
     pname = "fish";
-    version = "3.4.0";
+    version = "3.3.1";
 
     src = fetchurl {
       # There are differences between the release tarball and the tarball GitHub
@@ -144,9 +144,11 @@ let
       # --version`), as well as the local documentation for all builtins (and
       # maybe other things).
       url = "https://github.com/fish-shell/fish-shell/releases/download/${version}/${pname}-${version}.tar.xz";
-      sha256 = "sha256-tbSKuEhrGe9xajL39GuIuepTVhVfDpZ+6Z9Ak2RUE8U=";
+      sha256 = "sha256-tbTuGlJpdiy76ZOkvWUH5nXkEAzpu+hCFKXusrGfrok=";
     };
 
+    patches = [ ./tests-pcre2-update.patch ]; # should be included in >= 3.4
+
     # Fix FHS paths in tests
     postPatch = ''
       # src/fish_tests.cpp
diff --git a/pkgs/shells/fish/tests-pcre2-update.patch b/pkgs/shells/fish/tests-pcre2-update.patch
new file mode 100644
index 000000000000..5e0c327c540a
--- /dev/null
+++ b/pkgs/shells/fish/tests-pcre2-update.patch
@@ -0,0 +1,7 @@
+Adapted formating to 3.3.1 from
+https://github.com/fish-shell/fish-shell/commit/ec8844d834cc9fe626e9fc326c6f5410341d532a
+--- a/src/fish_tests.cpp
++++ b/src/fish_tests.cpp
+@@ -5726,2 +5725,0 @@
+-        {{L"string", L"match", L"-r", L"(?=ab\\K)", L"ab", 0}, STATUS_CMD_OK, L"\n"},
+-        {{L"string", L"match", L"-r", L"(?=ab\\K)..(?=cd\\K)", L"abcd", 0}, STATUS_CMD_OK, L"\n"},