diff --git a/mitogen/master.py b/mitogen/master.py
index fd0c4201..55a02b6e 100644
--- a/mitogen/master.py
+++ b/mitogen/master.py
@@ -522,9 +522,6 @@ class PkgutilMethod(FinderMethod):
 
             # workaround for special python modules that might only exist in memory
             if is_special and is_pkg and not source:
-                # jjj
-                # hope this raises an error
-                raise ValueError(fullname)
                 source = '\n'
         except (AttributeError, ImportError):
             # - Per PEP-302, get_source() and is_package() are optional,