X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib-python/blobdiff_plain/704500e11c6a7e240acc047607d34bc6db520f15..a19eaede18c9176b382df01e4f6c6e5c04a87d0f:/sym.pyx

diff --git a/sym.pyx b/sym.pyx
index 48ba3f0..eab6984 100644
--- a/sym.pyx
+++ b/sym.pyx
@@ -71,7 +71,7 @@ cdef class SymTable (Mapping):
 cdef class _SymIter (_MapIterator):
   cdef SymTable t
   cdef sym_iter i
-  def __cinit__(me, SymTable t):
+  def __cinit__(me, SymTable t not None):
     me.t = t
     sym_mkiter(&me.i, &me.t._t)
   cdef void *_next(me):