diff --git a/pkgs/development/libraries/readline/6.3.nix b/pkgs/development/libraries/readline/6.3.nix
index 73ed823d2be..1e5d9a0a664 100644
--- a/pkgs/development/libraries/readline/6.3.nix
+++ b/pkgs/development/libraries/readline/6.3.nix
@@ -12,13 +12,11 @@ stdenv.mkDerivation {
 
   propagatedBuildInputs = [ncurses];
 
-  patchFlags = "-p0";
+  patchFlags = [ "-p0" ];
 
-  configureFlags =
-    stdenv.lib.optional (stdenv.hostPlatform != stdenv.buildPlatform)
-    [ # This test requires running host code
-      "bash_cv_wcwidth_broken=no"
-    ];
+  configureFlags = stdenv.lib.optional (stdenv.hostPlatform != stdenv.buildPlatform)
+    # This test requires running host code
+    "bash_cv_wcwidth_broken=no";
 
   patches =
     [ ./link-against-ncurses.patch