Text to interval conversion can silently truncate data

jack=# select '1.51 years'::interval = '1.52 years'::interval;
 ?column?
----------
 t
(1 row)

This is surprising. Once I looked at the C code for Interval it makes more sense given that it cannot represent fractional years, months, or days. Wouldn't it make more sense to raise an invalid input error than to silently truncate data?

Jack