diff --git a/lib/libc/sys/posix_fallocate.2 b/lib/libc/sys/posix_fallocate.2
index 7b17133bd03..14607643d92 100644
--- a/lib/libc/sys/posix_fallocate.2
+++ b/lib/libc/sys/posix_fallocate.2
@@ -83,9 +83,9 @@ that reduces the file size to a size smaller than
 If successful,
 .Fn posix_fallocate
 returns zero.
-It returns -1 on failure, and sets
+It returns error number on failure, without setting
 .Va errno
-to indicate the error.
+variable.
 .Sh ERRORS
 Possible failure conditions:
 .Bl -tag -width Er
diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index 719a0573cb5..e4ffbe48e05 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -2995,8 +2995,9 @@ freebsd32_posix_fallocate(struct thread *td,
     struct freebsd32_posix_fallocate_args *uap)
 {
 
-	return (kern_posix_fallocate(td, uap->fd,
-	    PAIR32TO64(off_t, uap->offset), PAIR32TO64(off_t, uap->len)));
+	td->td_retval[0] = kern_posix_fallocate(td, uap->fd,
+	    PAIR32TO64(off_t, uap->offset), PAIR32TO64(off_t, uap->len));
+	return (0);
 }
 
 int
diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
index dbad1aede93..b864c904e37 100644
--- a/sys/kern/vfs_syscalls.c
+++ b/sys/kern/vfs_syscalls.c
@@ -4584,7 +4584,9 @@ int
 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap)
 {
 
-	return (kern_posix_fallocate(td, uap->fd, uap->offset, uap->len));
+	td->td_retval[0] = kern_posix_fallocate(td, uap->fd, uap->offset,
+	    uap->len);
+	return (0);
 }
 
 /*