diff --git a/pkgs/applications/window-managers/i3/default.nix b/pkgs/applications/window-managers/i3/default.nix
index 5c2db7d47a53..9a6fc5959548 100644
--- a/pkgs/applications/window-managers/i3/default.nix
+++ b/pkgs/applications/window-managers/i3/default.nix
@@ -1,5 +1,5 @@
 { fetchurl, lib, stdenv, pkg-config, makeWrapper, meson, ninja, installShellFiles, libxcb, xcbutilkeysyms
-, xcbutil, xcbutilwm, xcbutilxrm, libstartup_notification, libX11, pcre, libev
+, xcbutil, xcbutilwm, xcbutilxrm, libstartup_notification, libX11, pcre2, libev
 , yajl, xcb-util-cursor, perl, pango, perlPackages, libxkbcommon
 , xorgserver, xvfb-run
 , asciidoc, xmlto, docbook_xml_dtd_45, docbook_xsl, findXMLCatalogs
@@ -7,11 +7,11 @@
 
 stdenv.mkDerivation rec {
   pname = "i3";
-  version = "4.20.1";
+  version = "4.21";
 
   src = fetchurl {
     url = "https://i3wm.org/downloads/${pname}-${version}.tar.xz";
-    sha256 = "1rpwdgykcvmrmdz244f0wm7446ih1dcw8rlc1hm1c7cc42pyrq93";
+    sha256 = "sha256-jcUgXg80Q9WGYeMHg1If2cbUJtHn82Z6sS8qwbLTIHg=";
   };
 
   nativeBuildInputs = [
@@ -26,7 +26,7 @@ stdenv.mkDerivation rec {
 
   buildInputs = [
     libxcb xcbutilkeysyms xcbutil xcbutilwm xcbutilxrm libxkbcommon
-    libstartup_notification libX11 pcre libev yajl xcb-util-cursor perl pango
+    libstartup_notification libX11 pcre2 libev yajl xcb-util-cursor perl pango
     perlPackages.AnyEventI3 perlPackages.X11XCB perlPackages.IPCRun
     perlPackages.ExtUtilsPkgConfig perlPackages.InlineC
     xorgserver xvfb-run
diff --git a/pkgs/applications/window-managers/i3/gaps.nix b/pkgs/applications/window-managers/i3/gaps.nix
index faa325023f9f..64d863e8047f 100644
--- a/pkgs/applications/window-managers/i3/gaps.nix
+++ b/pkgs/applications/window-managers/i3/gaps.nix
@@ -2,13 +2,13 @@
 
 i3.overrideAttrs (oldAttrs : rec {
   pname = "i3-gaps";
-  version = "4.20.1";
+  version = "4.21";
 
   src = fetchFromGitHub {
     owner = "Airblader";
     repo = "i3";
     rev = version;
-    sha256 = "sha256-aS1dLs8KxoJaTf3RlQX+zRrtNmHEFZgkXDjt+8SuGDw=";
+    sha256 = "sha256-douSRvnyDbi2gDJfu9VZmmTyYfy+FrFWHgyAyPyBWdM=";
   };
 
   meta = with lib; {
diff --git a/pkgs/applications/window-managers/i3/rounded.nix b/pkgs/applications/window-managers/i3/rounded.nix
index 6ab3c29387f5..aa3701975fcc 100644
--- a/pkgs/applications/window-managers/i3/rounded.nix
+++ b/pkgs/applications/window-managers/i3/rounded.nix
@@ -1,4 +1,4 @@
-{ fetchFromGitHub, lib, i3 }:
+{ fetchFromGitHub, lib, i3, pcre }:
 
 i3.overrideAttrs (oldAttrs: rec {
   pname = "i3-rounded";
@@ -11,6 +11,8 @@ i3.overrideAttrs (oldAttrs: rec {
     sha256 = "0y7m1s1y8f9vgkp7byi33js8n4rigiykd71s936i5d4rwlzrxiwm";
   };
 
+  buildInputs = oldAttrs.buildInputs ++ [ pcre ];
+
   meta = with lib; {
     description = "A fork of i3-gaps that adds rounding to window corners";
     homepage = "https://github.com/LinoBigatti/i3-rounded";