  We consider compact binary systems in f(R) gravity theories in the Palatini
approach and calculate the post-Newtonian parameters to the 1.5PN order using
the method of Direct Integration of the Relaxed Einstein equations (DIRE). The
Palatini-type modifications of gravity can be formulated as Einsteins gravity
with modified response to matter sources, and it is shown in detail how to
treat these correctly within the DIRE formalism. Our results explicitly confirm
the expectation that for binary black holes the new effects can be absorbed
into redefinitions of the binary masses, rendering such systems observationally
identical to general relativity.
