diff --git a/pkgs/tools/networking/networkmanager/strongswan/default.nix b/pkgs/tools/networking/networkmanager/strongswan/default.nix
index e080ca17db13..545dd3d82cdc 100644
--- a/pkgs/tools/networking/networkmanager/strongswan/default.nix
+++ b/pkgs/tools/networking/networkmanager/strongswan/default.nix
@@ -38,6 +38,7 @@ stdenv.mkDerivation rec {
   ];
 
   configureFlags = [
+    "--disable-more-warnings" # disables -Werror
     "--with-charon=${strongswanNM}/libexec/ipsec/charon-nm"
     "--with-nm-libexecdir=${placeholder "out"}/libexec"
     "--with-nm-plugindir=${placeholder "out"}/lib/NetworkManager"