diff --git a/drivers/staging/comedi/drivers/ni_routes.c b/drivers/staging/comedi/drivers/ni_routes.c
index 673d732dcb8f..9627bd1d2a78 100644
--- a/drivers/staging/comedi/drivers/ni_routes.c
+++ b/drivers/staging/comedi/drivers/ni_routes.c
@@ -487,6 +487,9 @@ int ni_find_route_source(const u8 src_sel_reg_value, int dest,
 {
 	int src;
 
+	if (!tables->route_values)
+		return -EINVAL;
+
 	dest = B(dest); /* subtract NI names offset */
 	/* ensure we are not going to under/over run the route value table */
 	if (dest < 0 || dest >= NI_NUM_NAMES)