diff --git a/stack.nix b/stack.nix
index a9a2af3de..c78220b4c 100644
--- a/stack.nix
+++ b/stack.nix
@@ -8,7 +8,7 @@ in pkgs.haskell.lib.buildStackProject {
   inherit (haskellPackages) stack;
   name = "stackenv";
   buildInputs = (with pkgs;
-    [ postgresql zlib libsodium
+    [ postgresql zlib libsodium gmp
     ]) ++ (with haskellPackages;
     [ yesod-bin
     ]);