diff --git a/pkgs/by-name/pi/pigpio/package.nix b/pkgs/by-name/pi/pigpio/package.nix
index 9bd2683c82ec..a3ea10b44875 100644
--- a/pkgs/by-name/pi/pigpio/package.nix
+++ b/pkgs/by-name/pi/pigpio/package.nix
@@ -26,7 +26,7 @@ mkDerivation rec {
     hash = "sha256-Z+SwUlBbtWtnbjTe0IghR3gIKS43ZziN0amYtmXy7HE=";
   };
 
-  NIX_CFLAGS_COMPILE = "-std=gnu17";
+  env.NIX_CFLAGS_COMPILE = "-std=gnu17";
 
   nativeBuildInputs = [
     cmake