diff --git a/pkgs/by-name/li/libultrahdr/package.nix b/pkgs/by-name/li/libultrahdr/package.nix
index f63521ee4742..c4328f72fcfb 100644
--- a/pkgs/by-name/li/libultrahdr/package.nix
+++ b/pkgs/by-name/li/libultrahdr/package.nix
@@ -47,6 +47,13 @@ stdenv.mkDerivation (finalAttrs: {
     # Based on https://github.com/google/libultrahdr/pull/383
     # modified to target 1.4.0 instead of main
     ./remove-platform-and-detection-logic.patch
+
+    # fix tests on big-endian
+    # https://github.com/google/libultrahdr/pull/396
+    (fetchpatch {
+      url = "https://github.com/google/libultrahdr/commit/13a058f452d846e43d4691f6885eeeaa8b0ea8d0.patch";
+      hash = "sha256-2ZVvBMz8wQLEThuXdRJbbx5m2ouRZpxVWoH88RLmit4=";
+    })
   ];
 
   # CMake incorrect absolute include/lib paths: https://github.com/NixOS/nixpkgs/issues/144170