Index: head/bin/df/df.c
===================================================================
--- head/bin/df/df.c
+++ head/bin/df/df.c
@@ -254,9 +254,11 @@
 				rv = 1;
 				continue;
 			}
-#ifdef MOUNT_CHAR_DEVS
 		} else if (S_ISCHR(stbuf.st_mode)) {
 			if ((mntpt = getmntpt(*argv)) == NULL) {
+#ifdef MOUNT_CHAR_DEVS
+				xo_warnx(
+				    "df on unmounted devices is deprecated");
 				mdev.fspec = *argv;
 				mntpath = strdup("/tmp/df.XXXXXX");
 				if (mntpath == NULL) {
@@ -305,8 +307,12 @@
 				(void)rmdir(mntpt);
 				free(mntpath);
 				continue;
-			}
+#else
+				xo_warnx("%s: not mounted", *argv);
+				rv = 1;
+				continue;
 #endif
+			}
 		} else
 			mntpt = *argv;