diff --git a/pkgs/applications/networking/instant-messengers/telegram-cli/default.nix b/pkgs/applications/networking/instant-messengers/telegram-cli/default.nix
index b0302ba8e0bf..812f00829e27 100644
--- a/pkgs/applications/networking/instant-messengers/telegram-cli/default.nix
+++ b/pkgs/applications/networking/instant-messengers/telegram-cli/default.nix
@@ -12,6 +12,8 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ libconfig lua5_2 openssl readline zlib ];
 
+  NIX_CFLAGS_COMPILE = "-Wno-error=deprecated-declarations"; # CPPFunction
+
   installPhase = ''
     mkdir -p $out/bin
     cp ./telegram $out/bin/telegram-wo-key