diff --git a/Lib/perl5/perlrun.swg b/Lib/perl5/perlrun.swg
index b506c3af9..ecb1f5cd2 100644
--- a/Lib/perl5/perlrun.swg
+++ b/Lib/perl5/perlrun.swg
@@ -293,7 +293,7 @@ SWIG_Perl_ConvertPtrAndOwn(SWIG_MAYBE_PERL_OBJECT SV *sv, void **ptr, swig_type_
       int newmemory = 0;
       *ptr = SWIG_TypeCast(tc,voidptr,&newmemory);
       if (newmemory == SWIG_CAST_NEW_MEMORY) {
-        assert(own);
+        assert(own); /* badly formed typemap which will lead to a memory leak - it must set and use own to delete *ptr */
         if (own)
           *own = *own | SWIG_CAST_NEW_MEMORY;
       }
diff --git a/Lib/python/pyrun.swg b/Lib/python/pyrun.swg
index 21fddb610..c0d30ee45 100644
--- a/Lib/python/pyrun.swg
+++ b/Lib/python/pyrun.swg
@@ -1089,7 +1089,7 @@ SWIG_Python_ConvertPtrAndOwn(PyObject *obj, void **ptr, swig_type_info *ty, int
               int newmemory = 0;
               *ptr = SWIG_TypeCast(tc,vptr,&newmemory);
               if (newmemory == SWIG_CAST_NEW_MEMORY) {
-                assert(own);
+                assert(own); /* badly formed typemap which will lead to a memory leak - it must set and use own to delete *ptr */
                 if (own)
                   *own = *own | SWIG_CAST_NEW_MEMORY;
               }