diff --git a/pkgs/development/libraries/libb2/default.nix b/pkgs/development/libraries/libb2/default.nix
index f4d01def94a2..eae08f0071cb 100644
--- a/pkgs/development/libraries/libb2/default.nix
+++ b/pkgs/development/libraries/libb2/default.nix
@@ -3,6 +3,13 @@ with stdenv; with lib;
 mkDerivation rec {
   name = "libb2-${meta.version}";
 
+  src = fetchurl {
+    url = "https://blake2.net/${name}.tar.gz";
+    sha256 = "7829c7309347650239c76af7f15d9391af2587b38f0a65c250104a2efef99051";
+  };
+
+  configureFlags = [ "--enable-fat=yes" ];
+
   meta = {
     version = "0.97";
     description = "The BLAKE2 family of cryptographic hash functions";
@@ -10,9 +17,4 @@ mkDerivation rec {
     maintainers = with maintainers; [ dfoxfranke ];
     license = licenses.cc0;
   };
-
-  src = fetchurl {
-    url = "https://blake2.net/${name}.tar.gz";
-    sha256 = "7829c7309347650239c76af7f15d9391af2587b38f0a65c250104a2efef99051";
-  };
 }