diff --git a/var/spack/repos/builtin/packages/qmcpack/package.py b/var/spack/repos/builtin/packages/qmcpack/package.py
index f25a289a0f5ed4fceaf34cd93b6fc1564f93b487..8ce3e56de27961a66f403486eaaf91e6a0e45d1c 100644
--- a/var/spack/repos/builtin/packages/qmcpack/package.py
+++ b/var/spack/repos/builtin/packages/qmcpack/package.py
@@ -277,6 +277,7 @@ def cmake_args(self):
             args.append('-DENABLE_MKL=1')
             args.append('-DMKL_ROOT=%s' % env['MKLROOT'])
         else:
+            args.append('-DENABLE_MKL=0')
             lapack_dir = ':'.join((
                 spec['lapack'].prefix.include,
                 spec['blas'].prefix.include