diff --git a/build.nix b/build.nix
index d84f041..518f34a 100644
--- a/build.nix
+++ b/build.nix
@@ -1,6 +1,6 @@
 { pkgs, release }:
 
-{ simpleName, binName, attrName, completionName ? binName }:
+{ simpleName, binName, attrName }:
 
 let
   release = import ./release.nix;
@@ -25,6 +25,6 @@ pkgs.stdenv.mkDerivation rec {
     install -D -m555 -T ${binName} "$binPath"
 
     mkdir -p $out/etc/bash_completion.d/
-    "$binPath" --bash-completion-script "$binPath" > "$out/etc/bash_completion.d/${completionName}-completion.bash"
+    "$binPath" --bash-completion-script "$binPath" > "$out/etc/bash_completion.d/${binName}-completion.bash"
   '';
 }
diff --git a/dhall-yaml-simple.nix b/dhall-yaml-simple.nix
index 76739da..7fe8c33 100644
--- a/dhall-yaml-simple.nix
+++ b/dhall-yaml-simple.nix
@@ -4,5 +4,4 @@ import ./build.nix { inherit pkgs; release = import ./release.nix; } {
   simpleName = "dhall-yaml-simple";
   binName = "dhall-to-yaml-ng";
   attrName = "dhall-yaml";
-  completionName = "dhall-to-yaml";
 }