diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
index 3714d38c7..30a21685e 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -1445,7 +1445,7 @@ When the mapping is
 the
 .I data_tail
 value should be written by user space to reflect the last read data.
-In this case the kernel will not overwrite unread data.
+In this case, the kernel will not overwrite unread data.
 .PP
 The following 2^n ring-buffer pages have the layout described below.
 
@@ -2093,7 +2093,7 @@ or
 .I wakeup_watermark
 value that will generate a signal if a certain number of samples
 or bytes have been written to the mmap ring buffer.
-In this case a signal of type
+In this case, a signal of type
 .B POLL_IN
 is sent.