diff --git a/src/stdlib/qsort.c b/src/stdlib/qsort.c
index 434d9350726df8413295db92846d37ac7f63a2f4..da58fd3177814634d7e1b9b06ea2135ee633295f 100644
--- a/src/stdlib/qsort.c
+++ b/src/stdlib/qsort.c
@@ -21,6 +21,9 @@
 
 /* Minor changes by Rich Felker for integration in musl, 2011-04-27. */
 
+/* Smoothsort, an adaptive variant of Heapsort.  Memory usage: O(1).
+   Run time: Worst case O(n log n), close to O(n) in the mostly-sorted case. */
+
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>