diff --git a/erfa/ufunc.c.templ b/erfa/ufunc.c.templ
index 977045a..26f7a0f 100644
--- a/erfa/ufunc.c.templ
+++ b/erfa/ufunc.c.templ
@@ -17,6 +17,8 @@
 #include "erfa.h"
 #include "erfaextra.h"
 
+struct _typeobject {};
+
 #define MODULE_DOCSTRING \
     "Ufunc wrappers of the ERFA routines.\n\n" \
     "These ufuncs vectorize the ERFA functions assuming structured dtypes\n" \