diff --git a/var/spack/repos/builtin/packages/perl/package.py b/var/spack/repos/builtin/packages/perl/package.py
index 40b31e12376..56276cbacde 100644
--- a/var/spack/repos/builtin/packages/perl/package.py
+++ b/var/spack/repos/builtin/packages/perl/package.py
@@ -230,7 +230,7 @@ def nmake_arguments(self):
         return args
 
     def is_64bit(self):
-        return "64" in str(self.pkg.spec.target.family)
+        return "64" in str(self.spec.target.family)
 
     def configure_args(self):
         spec = self.spec