diff --git a/pkgs/by-name/ke/kermit/package.nix b/pkgs/by-name/ke/kermit/package.nix
index 5dcbe23d9eb6..b68c09f33a29 100644
--- a/pkgs/by-name/ke/kermit/package.nix
+++ b/pkgs/by-name/ke/kermit/package.nix
@@ -39,6 +39,8 @@ stdenv.mkDerivation {
     make -f makefile install
   '';
 
+  env.NIX_CFLAGS_COMPILE = "-Wno-implicit-function-declaration -Wno-implicit-int";
+
   meta = with lib; {
     homepage = "https://www.kermitproject.org/ck90.html";
     description = "Portable Scriptable Network and Serial Communication Software";