Setting timeout to Qt Test

I'm using Qt Test, for write unit tests for some computing heavy algorithms. The process uses a considerable amount of time, and when is run in a older computer, the process fails because a timeout like this:

********* Start testing of KnotTest *********
Config: Using QtTest library 5.6.2, Qt 5.6.2 (i386-little_endian-ilp32 shared (dynamic) release build; by MSVC 2013)
PASS   : MyTest::initTestCase()
QFATAL : MyTest::test_benchmark() Test function timed out
FAIL!  : MyTest::test_benchmark() Received a fatal error.
Unknown file(0) : failure location
Totals: 1 passed, 1 failed, 0 skipped, 0 blacklisted
********* Finished testing of KnotTest *********

How can set a custom timeout for the test program generated?