diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index d5a1b095c372..d54751908a46 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -507,7 +507,7 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
 		}
 
 		/*
-		 * We deffinately must sleep for this lock.
+		 * We definitely must sleep for this lock.
 		 */
 		mtx_assert(m, MA_NOTOWNED);
 
diff --git a/sys/kern/subr_turnstile.c b/sys/kern/subr_turnstile.c
index d5a1b095c372..d54751908a46 100644
--- a/sys/kern/subr_turnstile.c
+++ b/sys/kern/subr_turnstile.c
@@ -507,7 +507,7 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
 		}
 
 		/*
-		 * We deffinately must sleep for this lock.
+		 * We definitely must sleep for this lock.
 		 */
 		mtx_assert(m, MA_NOTOWNED);