diff --git a/pkgs/by-name/fa/fasthenry/package.nix b/pkgs/by-name/fa/fasthenry/package.nix
index aaea2c87ae13..4ed15bdff8c0 100644
--- a/pkgs/by-name/fa/fasthenry/package.nix
+++ b/pkgs/by-name/fa/fasthenry/package.nix
@@ -27,6 +27,8 @@ stdenv.mkDerivation (finalAttrs: {
     "-Wno-error=implicit-function-declaration"
     "-Wno-error=implicit-int"
     "-Wno-error=return-mismatch"
+    # gcc15
+    "-std=gnu17"
   ];
 
   makeFlags = [ "all" ]; # need "all" to be explicitely set