On Jun 14, 6:41 ¨Βν¬ ΠετεΪοτοΌχθιτερυ®®®ΐχθιτερυαςλ®ςυΎ χςοτεΊ > Why do not use ruby array (rb_array_new) as MyOtherStruct? > This may help (just need to keep one object instead of bunch of them...) I may end up doing that, but this is puzzling behavior, and I'd like to figure out what's causing subsequent object allocations in the callback chain to overwrite the original rb_hash_new(). I'd like to know for future reference what's going on here.