diff --git a/pkgs/by-name/yt/ytalk/package.nix b/pkgs/by-name/yt/ytalk/package.nix
index df1088382fbc..b51cb196f4c6 100644
--- a/pkgs/by-name/yt/ytalk/package.nix
+++ b/pkgs/by-name/yt/ytalk/package.nix
@@ -16,6 +16,8 @@ stdenv.mkDerivation (finalAttrs: {
 
   buildInputs = [ ncurses ];
 
+  env.NIX_CFLAGS_COMPILE = "-std=gnu17";
+
   meta = {
     homepage = "http://ytalk.ourproject.org";
     description = "Terminal based talk client";