Planner not pushing some predicates with constant exprs to Kudu

The following query is unable to push to Kudu:

select count(*) from metrics where `timestamp` < 1475059765 + 10

Oddly, the following one works fine:

select count(*) from metrics where `timestamp` < 1000 + 10

I'm guessing that some kind of implicit CAST is getting inserted here which is blocking the pushdown. 'timestamp' is an 'int' column here.