diff --git a/libcutils/sched_policy.cpp b/libcutils/sched_policy.cpp
index e29a8444c..7e385355f 100644
--- a/libcutils/sched_policy.cpp
+++ b/libcutils/sched_policy.cpp
@@ -340,7 +340,7 @@ int set_cpuset_policy(int tid, SchedPolicy policy)
     return 0;
 }
 
-static void set_timerslack_ns(int tid, unsigned long long slack) {
+static void set_timerslack_ns(int tid, unsigned long slack) {
     // v4.6+ kernels support the /proc/<tid>/timerslack_ns interface.
     // TODO: once we've backported this, log if the open(2) fails.
     if (__sys_supports_timerslack) {
@@ -348,7 +348,7 @@ static void set_timerslack_ns(int tid, unsigned long long slack) {
         snprintf(buf, sizeof(buf), "/proc/%d/timerslack_ns", tid);
         int fd = open(buf, O_WRONLY | O_CLOEXEC);
         if (fd != -1) {
-            int len = snprintf(buf, sizeof(buf), "%llu", slack);
+            int len = snprintf(buf, sizeof(buf), "%lu", slack);
             if (write(fd, buf, len) != len) {
                 SLOGE("set_timerslack_ns write failed: %s\n", strerror(errno));
             }