diff --git a/var/spack/repos/builtin/packages/cbflib/package.py b/var/spack/repos/builtin/packages/cbflib/package.py
index f0b83a07a1e..4ec7b02a33d 100644
--- a/var/spack/repos/builtin/packages/cbflib/package.py
+++ b/var/spack/repos/builtin/packages/cbflib/package.py
@@ -43,6 +43,9 @@ def edit(self, spec, prefix):
         mf.filter(r"^C\+\+.+", "C++ = {0}".format(spack_cxx))
         mf.filter("gfortran", spack_fc)
         mf.filter(r"^INSTALLDIR .+", "INSTALLDIR = {0}".format(prefix))
+        real_version = Version(self.compiler.get_real_version())
+        if real_version >= Version("10"):
+            mf.filter(r"^F90FLAGS[ \t]*=[ \t]*(.+)", "F90FLAGS = \\1 -fallow-invalid-boz")
 
     def build(self, spec, prefix):
         pass