diff --git a/pkgs/by-name/li/libetpan/package.nix b/pkgs/by-name/li/libetpan/package.nix
index c9f3a1566389..bc1f6c6e9bd9 100644
--- a/pkgs/by-name/li/libetpan/package.nix
+++ b/pkgs/by-name/li/libetpan/package.nix
@@ -104,6 +104,8 @@ stdenv.mkDerivation (finalAttrs: {
 
   buildInputs = [ openssl ];
 
+  configureFlags = [ "CFLAGS=-std=gnu17" ];
+
   configureScript = "./autogen.sh";
 
   meta = {