diff --git a/pkgs/by-name/z8/z88dk/package.nix b/pkgs/by-name/z8/z88dk/package.nix
index 9f987a04ce21..4699bf91b1a4 100644
--- a/pkgs/by-name/z8/z88dk/package.nix
+++ b/pkgs/by-name/z8/z88dk/package.nix
@@ -136,6 +136,10 @@ stdenv.mkDerivation (finalAttrs: {
     rm src/z80asm/t/z80asm_lib.t
   '';
 
+  # z88dk-z80asm triggers buffer overflow detection with FORTIFY_SOURCE=3.
+  # Upstream bug: https://github.com/z88dk/z88dk/issues/3042
+  hardeningDisable = [ "fortify" ];
+
   # Parallel building is not working yet with the upstream Makefiles.
   # Explicitly switch this off for now.
   enableParallelBuilding = false;