diff --git a/sys/amd64/amd64/support.S b/sys/amd64/amd64/support.S
index e5740681e4e8..cc72cc07bd84 100644
--- a/sys/amd64/amd64/support.S
+++ b/sys/amd64/amd64/support.S
@@ -205,7 +205,7 @@ END(memcmp)
  * rsi - source
  * rdx - count
  *
- * The macro possibly clobbers the above and: rcx, r8, r9, 10
+ * The macro possibly clobbers the above and: rcx, r8, r9, r10
  * It does not clobber rax nor r11.
  */
 .macro MEMMOVE erms overlap begin end