diff --git a/pkgs/development/libraries/icu/base.nix b/pkgs/development/libraries/icu/base.nix
index 47ca63fca990..e51224433e8b 100644
--- a/pkgs/development/libraries/icu/base.nix
+++ b/pkgs/development/libraries/icu/base.nix
@@ -1,4 +1,4 @@
-{ version, sha256, patches ? [], patchFlags ? "" }:
+{ version, sha256, patches ? [], patchFlags ? [] }:
 { stdenv, lib, fetchurl, fixDarwinDylibNames
   # Cross-compiled icu4c requires a build-root of a native compile
 , buildRootOnly ? false, nativeBuildRoot