diff --git a/var/spack/repos/builtin/packages/h5z-zfp/package.py b/var/spack/repos/builtin/packages/h5z-zfp/package.py
index 943c874e4bd..2b0283f1d47 100644
--- a/var/spack/repos/builtin/packages/h5z-zfp/package.py
+++ b/var/spack/repos/builtin/packages/h5z-zfp/package.py
@@ -33,6 +33,8 @@ def make_defs(self):
 
         if '+fortran' in self.spec and spack_fc:
             make_defs += ['FC=%s' % spack_fc]
+        else:
+            make_defs += ['FC=']
 
         return make_defs