diff --git a/src/evalfunc.c b/src/evalfunc.c
index 1991aa7..25b28bb 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -13348,6 +13348,9 @@
 {
     int		binary = FALSE;
     int		append = FALSE;
+#ifdef HAVE_FSYNC
+    int		do_fsync = p_fs;
+#endif
     char_u	*fname;
     FILE	*fd;
     int		ret = 0;
@@ -13380,6 +13383,12 @@
 	    binary = TRUE;
 	if (vim_strchr(arg2, 'a') != NULL)
 	    append = TRUE;
+#ifdef HAVE_FSYNC
+	if (vim_strchr(arg2, 's') != NULL)
+	    do_fsync = TRUE;
+	else if (vim_strchr(arg2, 'S') != NULL)
+	    do_fsync = FALSE;
+#endif
     }
 
     fname = get_tv_string_chk(&argvars[1]);
@@ -13398,6 +13407,10 @@
     {
 	if (write_list(fd, list, binary) == FAIL)
 	    ret = -1;
+#ifdef HAVE_FSYNC
+	else if (do_fsync && fsync(fileno(fd)) != 0)
+	    EMSG(_(e_fsync));
+#endif
 	fclose(fd);
     }