diff --git a/pkgs/tools/networking/unbound/default.nix b/pkgs/tools/networking/unbound/default.nix
index 1f135aecd851d8..a1a908340003b8 100644
--- a/pkgs/tools/networking/unbound/default.nix
+++ b/pkgs/tools/networking/unbound/default.nix
@@ -1,6 +1,7 @@
 { stdenv
 , lib
 , fetchurl
+, fetchpatch
 , openssl
 , nettle
 , expat
@@ -55,6 +56,15 @@ stdenv.mkDerivation rec {
     hash = "sha256-PalUkKhc/2Qg8m+uC4Skn1ES3xvxt/w0+HJPAggstxI=";
   };
 
+  patches = [
+    # Backport: fix libunbound with nettle.
+    (fetchpatch {
+      url = "https://github.com/NLnetLabs/unbound/commit/654a7eab62cbd1844d483cc4a0f2cf2fbcbaf00a.patch";
+      excludes = [ "doc/Changelog" ];
+      hash = "sha256-n3FCeZESFrrn6Wcf28Hb8WZs1eMHWjbsf2WCFOXU3lI=";
+    })
+  ];
+
   outputs = [ "out" "lib" "man" ]; # "dev" would only split ~20 kB
 
   nativeBuildInputs = [ makeWrapper pkg-config ]