diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
index ea5ee725f..aea825706 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -3439,7 +3439,7 @@ main(int argc, char **argv)
     printf("Measuring instruction count for this printf\en");
 
     ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
-    read(fd, &count, sizeof(long long));
+    read(fd, &count, sizeof(count));
 
     printf("Used %lld instructions\en", count);