Index: uspace/app/perf/perf.c
===================================================================
--- uspace/app/perf/perf.c	(revision 858469fc68e54e82d128f5b7294b99375ad3f639)
+++ uspace/app/perf/perf.c	(revision 79bb48e29700cebe4c047377d62d33cff0357a43)
@@ -52,9 +52,9 @@
 
 static void short_report(stopwatch_t *stopwatch, int run_index,
-    benchmark_t *bench, size_t workload_size)
+    benchmark_t *bench, uint64_t workload_size)
 {
 	usec_t duration_usec = NSEC2USEC(stopwatch_get_nanos(stopwatch));
 
-	printf("Completed %zu operations in %llu us",
+	printf("Completed %" PRIu64 " operations in %llu us",
 	    workload_size, duration_usec);
 	if (duration_usec > 0) {
@@ -68,5 +68,5 @@
 
 static void summary_stats(stopwatch_t *stopwatch, size_t stopwatch_count,
-    benchmark_t *bench, size_t workload_size)
+    benchmark_t *bench, uint64_t workload_size)
 {
 	double sum = 0.0;