1 files changed, 1 insertions, 1 deletions
diff --git a/pkgs/development/libraries/science/math/ipopt/default.nix b/pkgs/development/libraries/science/math/ipopt/default.nix
index 647fd82ec0e..97374fb0d47 100644
--- a/pkgs/development/libraries/science/math/ipopt/default.nix
+++ b/pkgs/development/libraries/science/math/ipopt/default.nix
@@ -1,6 +1,6 @@
 { stdenv, fetchurl, unzip, blas, lapack, gfortran }:
 
-assert (!blas.is64bit) && (!lapack.is64bit);
+assert (!blas.isILP64) && (!lapack.isILP64);
 
 stdenv.mkDerivation rec {
   pname = "ipopt";