Index: generic/nsf.c
===================================================================
diff -u -N -rd66258cafa0a21e1b10fa42951de7e71f63a1817 -rb0bfe3f3bf2e7fd2c14c58eeedca34b734803ecd
--- generic/nsf.c	(.../nsf.c)	(revision d66258cafa0a21e1b10fa42951de7e71f63a1817)
+++ generic/nsf.c	(.../nsf.c)	(revision b0bfe3f3bf2e7fd2c14c58eeedca34b734803ecd)
@@ -21417,18 +21417,43 @@
    * Omit storm of invalidations on shutdown.
    */
   if (unlikely(RUNTIME_STATE(interp)->exitHandlerDestroyRound == NSF_EXITHANDLER_OFF)) {
-    NsfClasses *subClasses = TransitiveSubClasses(cl), *clPtr;
+    Tcl_HashTable objTable, *commandTable = &objTable;
+    Tcl_HashSearch hSrch;
+    Tcl_HashEntry *hPtr;
+
+    /* NsfClasses *subClasses = TransitiveSubClasses(cl), *clPtr; */
+  
     /*
      * invalidate cached parameters in subclasses
-     */
-    for (clPtr = subClasses; clPtr; clPtr = clPtr->nextPtr) {
+     *
+     for (clPtr = subClasses; clPtr; clPtr = clPtr->nextPtr) {
       NsfClass *subClass = clPtr->cl;
       if (subClass->parsedParamPtr) {
         ParsedParamFree(subClass->parsedParamPtr);
         subClass->parsedParamPtr = NULL;
       }
     }
     NsfClassListFree(subClasses);
+   */
+
+    Tcl_InitHashTable(commandTable, TCL_ONE_WORD_KEYS);
+    MEM_COUNT_ALLOC("Tcl_InitHashTable", commandTable);
+    GetAllClassMixinsOf(interp, commandTable, Tcl_GetObjResult(interp),
+		      cl, 1, 0, NULL, NULL);
+
+    for (hPtr = Tcl_FirstHashEntry(commandTable, &hSrch); hPtr;
+         hPtr = Tcl_NextHashEntry(&hSrch)) {
+      NsfClass *mixinOfClass = (NsfClass *)Tcl_GetHashKey(commandTable, hPtr);
+      if (mixinOfClass) {
+        /* fprintf(stderr, "mixinOfClass   %s\n", ClassName(mixinOfClass)); */
+        if (mixinOfClass->parsedParamPtr) {
+          ParsedParamFree(mixinOfClass->parsedParamPtr);
+          mixinOfClass->parsedParamPtr = NULL;
+        }
+      }
+    }
+    Tcl_DeleteHashTable(commandTable);
+    MEM_COUNT_FREE("Tcl_InitHashTable", commandTable);
   }
 
   return TCL_OK;
Index: tests/properties.test
===================================================================
diff -u -N -rd66258cafa0a21e1b10fa42951de7e71f63a1817 -rb0bfe3f3bf2e7fd2c14c58eeedca34b734803ecd
--- tests/properties.test	(.../properties.test)	(revision d66258cafa0a21e1b10fa42951de7e71f63a1817)
+++ tests/properties.test	(.../properties.test)	(revision b0bfe3f3bf2e7fd2c14c58eeedca34b734803ecd)
@@ -873,7 +873,53 @@
   ? {b1 configure -y 2} ""
 }
 
+nx::test case extend-class-mixin-info {
+  
+  nx::Class create Baz
+  nx::Class create Foo -mixin Baz
+  nx::Class create Bar -mixin Foo
+  Bar create bar; # cache becomes hot!
+  ? {llength [Bar info configure parameters]} 4
 
+  Foo property y
+  ? {llength [Bar info configure parameters]} 5
+
+  Baz property z
+  ? {llength [Bar info configure parameters]} 6
+
+  Baz delete property z
+  ? {llength [Bar info configure parameters]} 5
+
+  Foo delete property y
+  ? {llength [Bar info configure parameters]} 4
+
+}
+
+nx::test case extend-class-mixin-configure {
+  
+  nx::Class create Baz
+  nx::Class create Foo -mixin Baz
+  nx::Class create Bar -mixin Foo
+  Bar create bar; # cache becomes hot!
+
+  Foo property y
+  bar configure -y 1
+  ? {bar cget -y} 1
+
+  Baz property z
+  bar configure -z 2
+  ? {bar cget -z} 2
+  bar configure -y 3
+  ? {bar cget -y} 3
+
+  Bar property w
+  bar configure -w 4
+  ? {bar cget -w} 4
+
+}
+
+
+
 #
 # Local variables:
 #    mode: tcl