diff --git a/sys/kern/subr_physmem.c b/sys/kern/subr_physmem.c
index a45c36aef2d7..059566f0eccb 100644
--- a/sys/kern/subr_physmem.c
+++ b/sys/kern/subr_physmem.c
@@ -177,7 +177,8 @@ physmem_print_tables(void)
  *
  * Updates the value at *pavail with the sum of all pages in all hw regions.
  *
- * Returns the number of pages of non-excluded memory added to the avail list.
+ * Returns the number of entries in the avail list, which is twice the number
+ * of returned regions.
  */
 static size_t
 regions_to_avail(vm_paddr_t *avail, uint32_t exflags, size_t maxavail,