Index: generic/xotcl.c
===================================================================
diff -u -rc2009f0e35930ef9ea62a98f2b2133915837062f -rc4c111810ca8fbcf8539bde583c3877be79e4421
--- generic/xotcl.c	(.../xotcl.c)	(revision c2009f0e35930ef9ea62a98f2b2133915837062f)
+++ generic/xotcl.c	(.../xotcl.c)	(revision c4c111810ca8fbcf8539bde583c3877be79e4421)
@@ -7356,6 +7356,7 @@
     /* remove dependent filters of this class from all subclasses*/
     FilterRemoveDependentFilterCmds(cl, cl);
     AssertionRemoveStore(clopt->assertions);
+    clopt->assertions = NULL;
 #ifdef XOTCL_OBJECTDATA
     XOTclFreeObjectData(cl);
 #endif