diff --git a/ringbuf/reader_test.go b/ringbuf/reader_test.go
index bed7d0096..131336802 100644
--- a/ringbuf/reader_test.go
+++ b/ringbuf/reader_test.go
@@ -59,7 +59,7 @@ func TestRingbufReader(t *testing.T) {
 			}
 			defer rd.Close()
 
-			if uint32(rd.BufferSize()) != 2*events.MaxEntries() {
+			if uint32(rd.BufferSize()) != events.MaxEntries() {
 				t.Errorf("expected %d BufferSize, got %d", events.MaxEntries(), rd.BufferSize())
 			}
 
diff --git a/ringbuf/ring.go b/ringbuf/ring.go
index 35534c51e..4b062ce78 100644
--- a/ringbuf/ring.go
+++ b/ringbuf/ring.go
@@ -77,8 +77,11 @@ func (rr *ringReader) isEmpty() bool {
 	return prod == cons
 }
 
+// To be able to wrap around data, data pages in ring buffers are mapped twice in
+// a single contiguous virtual region.
+// Therefore the returned usable size is half the size of the mmaped region.
 func (rr *ringReader) size() int {
-	return cap(rr.ring)
+	return cap(rr.ring) / 2
 }
 
 // Read a record from an event ring.