diff --git a/nix/coloquinte.nix b/nix/coloquinte.nix
index b3748290..6ef37f7b 100644
--- a/nix/coloquinte.nix
+++ b/nix/coloquinte.nix
@@ -12,5 +12,7 @@ stdenv.mkDerivation {
   buildInputs = [ boostWithPython coriolis-bootstrap qt4 ];
   nativeBuildInputs = [ cmake ninja doxygen ];
 
+  cmakeFlags = [ "-DWITH_OPENMP:STRING=TRUE" ];
+
   inherit version meta;
 }