diff --git a/pkgs/tools/misc/lrzsz/default.nix b/pkgs/tools/misc/lrzsz/default.nix
index e097ab12f082..867e492b33e2 100644
--- a/pkgs/tools/misc/lrzsz/default.nix
+++ b/pkgs/tools/misc/lrzsz/default.nix
@@ -25,6 +25,8 @@ stdenv.mkDerivation rec {
 
   configureFlags = [ "--program-transform-name=s/^l//" ];
 
+  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-error=implicit-function-declaration -Wno-error=implicit-int";
+
   meta = with lib; {
     homepage = "https://ohse.de/uwe/software/lrzsz.html";
     description = "Communication package providing the XMODEM, YMODEM ZMODEM file transfer protocols";