diff --git a/var/spack/repos/builtin/packages/ntpoly/package.py b/var/spack/repos/builtin/packages/ntpoly/package.py
index 1fb459a6104..d390e19dba9 100644
--- a/var/spack/repos/builtin/packages/ntpoly/package.py
+++ b/var/spack/repos/builtin/packages/ntpoly/package.py
@@ -26,4 +26,7 @@ class Ntpoly(CMakePackage):
 
     def cmake_args(self):
         args = ["-DNOSWIG=Yes"]
+        if self.spec.satisfies('%fj'):
+            args.append('-DCMAKE_Fortran_MODDIR_FLAG=-M')
+
         return args