diff --git a/pkgs/tools/networking/openvpn/openvpn-auth-ldap.nix b/pkgs/tools/networking/openvpn/openvpn-auth-ldap.nix
index 818eadf2483f..1abfe2af14a6 100644
--- a/pkgs/tools/networking/openvpn/openvpn-auth-ldap.nix
+++ b/pkgs/tools/networking/openvpn/openvpn-auth-ldap.nix
@@ -29,6 +29,11 @@ stdenv.mkDerivation rec {
       url = "https://patch-diff.githubusercontent.com/raw/threerings/openvpn-auth-ldap/pull/92.patch";
       hash = "sha256-SXuo1D/WywKO5hCsmoeDdTsR7EelxFxJAKmlAQJ6vuE=";
     })
+    (fetchpatch2 {
+      name = "gcc-15-fix";
+      url = "https://sources.debian.org/data/main/o/openvpn-auth-ldap/2.0.4-5/debian/patches/gcc-15.patch";
+      hash = "sha256-VwUwRBBfxgxEO4PKC/97vEN4e6XcUG6esc0Khu+iDxM=";
+    })
   ];
 
   # clang > 17 dropped support for `-export-dynamic` but `-rdynamic` does the