Index: library/mongodb/nsfmongo.c
===================================================================
diff -u -N -rbfc9f64e6e94f265a27a32d5f7faf0763ae1c9e3 -r5c3834b15078b31970db26d0c65030ed1f66b18d
--- library/mongodb/nsfmongo.c	(.../nsfmongo.c)	(revision bfc9f64e6e94f265a27a32d5f7faf0763ae1c9e3)
+++ library/mongodb/nsfmongo.c	(.../nsfmongo.c)	(revision 5c3834b15078b31970db26d0c65030ed1f66b18d)
@@ -670,7 +670,7 @@
   /* TODO: examples in mongo-client do not touch out; do we have to do
      something about it? */
 
-  Tcl_SetObjResult(interp, Tcl_NewBooleanObj(success));
+  Tcl_SetObjResult(interp, Tcl_NewBooleanObj(success == MONGO_OK));
   return TCL_OK;
 }
 
@@ -821,7 +821,7 @@
 static int 
 NsfMongoUpdate(Tcl_Interp *interp, mongo *connPtr, CONST char *namespace, 
 	       Tcl_Obj *conditionObj, Tcl_Obj *valuesObj, int withUpsert, int withAll) {
-  int objc, result, options = 0;
+  int objc, result, mongorc, options = 0;
   Tcl_Obj **objv;
   bson cond[1], values[1];
 
@@ -844,8 +844,10 @@
   if (withAll) {options |= 2;}
 
   /* for the time being, no write_concern (last arg of mongo_update()) */
-  mongo_update(connPtr, namespace, cond, values, options, NULL);
-  
+  mongorc = mongo_update(connPtr, namespace, cond, values, options, NULL);
+
+  Tcl_SetObjResult(interp, Tcl_NewBooleanObj(mongorc == MONGO_OK));
+ 
   return TCL_OK;
 }