diff --git a/sys/dev/ppbus/lpt.c b/sys/dev/ppbus/lpt.c
index b83cc03474f4..a7f8dd97767e 100644
--- a/sys/dev/ppbus/lpt.c
+++ b/sys/dev/ppbus/lpt.c
@@ -695,6 +695,11 @@ lptread(dev_t dev, struct uio *uio, int ioflag)
         device_t ppbus = device_get_parent(lptdev);
 	int error = 0, len;
 
+	if (sc->sc_flags & LP_BYPASS) {
+		/* we can't do reads in bypass mode */
+		return (EPERM);
+	}
+
 	if ((error = ppb_1284_negociate(ppbus, PPB_NIBBLE, 0)))
 		return (error);