diff --git a/tools/perf/scripts/python/futex-contention.py b/tools/perf/scripts/python/futex-contention.py
index 11e70a3..0f5cf43 100644
--- a/tools/perf/scripts/python/futex-contention.py
+++ b/tools/perf/scripts/python/futex-contention.py
@@ -21,7 +21,7 @@
 lock_waits = {} # long-lived stats on (tid,lock) blockage elapsed time
 process_names = {} # long-lived pid-to-execname mapping
 
-def syscalls__sys_enter_futex(event, ctxt, cpu, s, ns, tid, comm,
+def syscalls__sys_enter_futex(event, ctxt, cpu, s, ns, tid, comm, callchain,
 			      nr, uaddr, op, val, utime, uaddr2, val3):
 	cmd = op & FUTEX_CMD_MASK
 	if cmd != FUTEX_WAIT:
@@ -31,7 +31,7 @@
 	thread_thislock[tid] = uaddr
 	thread_blocktime[tid] = nsecs(s, ns)
 
-def syscalls__sys_exit_futex(event, ctxt, cpu, s, ns, tid, comm,
+def syscalls__sys_exit_futex(event, ctxt, cpu, s, ns, tid, comm, callchain,
 			     nr, ret):
 	if thread_blocktime.has_key(tid):
 		elapsed = nsecs(s, ns) - thread_blocktime[tid]