diff --git a/nixos/modules/virtualisation/docker.nix b/nixos/modules/virtualisation/docker.nix
index 3eb0de3a8559..954e33ff24a3 100644
--- a/nixos/modules/virtualisation/docker.nix
+++ b/nixos/modules/virtualisation/docker.nix
@@ -150,6 +150,10 @@ in
 
   config = mkIf cfg.enable (mkMerge [{
       boot.kernelModules = [ "bridge" "veth" ];
+      boot.kernel.sysctl = {
+        "net.ipv4.conf.all.forwarding" = mkOverride 99 true;
+        "net.ipv4.conf.default.forwarding" = mkOverride 99 true;
+      };
       environment.systemPackages = [ cfg.package ]
         ++ optional cfg.enableNvidia pkgs.nvidia-docker;
       users.groups.docker.gid = config.ids.gids.docker;
diff --git a/nixos/tests/docker.nix b/nixos/tests/docker.nix
index 58e33535ed31..dee7480eb4a9 100644
--- a/nixos/tests/docker.nix
+++ b/nixos/tests/docker.nix
@@ -45,5 +45,8 @@ import ./make-test-python.nix ({ pkgs, ...} : {
 
     # Must match version 4 times to ensure client and server git commits and versions are correct
     docker.succeed('[ $(docker version | grep ${pkgs.docker.version} | wc -l) = "4" ]')
+    docker.succeed("systemctl restart systemd-sysctl")
+    docker.succeed("grep 1 /proc/sys/net/ipv4/conf/all/forwarding")
+    docker.succeed("grep 1 /proc/sys/net/ipv4/conf/default/forwarding")
   '';
 })