diff --git a/pkgs/games/openttd/default.nix b/pkgs/games/openttd/default.nix
index 4a5e15514124..47e607e42159 100644
--- a/pkgs/games/openttd/default.nix
+++ b/pkgs/games/openttd/default.nix
@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchzip,
+  fetchpatch,
   cmake,
   pkg-config,
   SDL2,
@@ -71,6 +72,16 @@ stdenv.mkDerivation rec {
     hash = "sha256-YT4IE/rJ9pnpeMWKbOra6AbSUwW19RwOKlXkxwoMeKY=";
   };
 
+  patches = [
+    # Fix build against icu-76:
+    #   https://github.com/OpenTTD/OpenTTD/pull/13048
+    (fetchpatch {
+      name = "icu-75.patch";
+      url = "https://github.com/OpenTTD/OpenTTD/commit/14fac2ad37bfb9cec56b4f9169d864f6f1c7b96e.patch";
+      hash = "sha256-L35ybnTKPO+HVP/7ZYzWM2mA+s1RAywhofSuzpy/6sc=";
+    })
+  ];
+
   nativeBuildInputs = [
     cmake
     pkg-config
diff --git a/pkgs/games/openttd/jgrpp.nix b/pkgs/games/openttd/jgrpp.nix
index d1e89f298e5c..7a47074e00e9 100644
--- a/pkgs/games/openttd/jgrpp.nix
+++ b/pkgs/games/openttd/jgrpp.nix
@@ -10,6 +10,7 @@ openttd.overrideAttrs (oldAttrs: rec {
     rev = "jgrpp-${version}";
     hash = "sha256-aEmuwWNxqjuLmiWMrqwTUtCwdwDMA00eQspCHntxEXw=";
   };
+  patches = [];
 
   buildInputs = oldAttrs.buildInputs ++ [ zstd ];