diff --git a/shell.nix b/shell.nix
index d174c926b272..554f9951164a 100644
--- a/shell.nix
+++ b/shell.nix
@@ -53,7 +53,7 @@ mkShell {
   name = "qmk-firmware";
 
   buildInputs = [ clang-tools_12 dfu-programmer dfu-util diffutils git pythonEnv niv ]
-    ++ lib.optional avr [
+    ++ lib.optionals avr [
       pkgsCross.avr.buildPackages.binutils
       pkgsCross.avr.buildPackages.gcc8
       avrlibc