diff --git a/syscall.c b/syscall.c
index 695873f..2a037d1 100644
--- a/syscall.c
+++ b/syscall.c
@@ -40,7 +40,7 @@ fetchstr(struct proc *p, uint addr, char **pp)
   return -1;
 }
 
-// Fetch the argno'th 32-bit system call argument.
+// Fetch the nth 32-bit system call argument.
 int
 argint(int n, int *ip)
 {