diff --git a/libsigrok.h b/libsigrok.h
index a606dfb0..fba6c9cc 100644
--- a/libsigrok.h
+++ b/libsigrok.h
@@ -636,6 +636,12 @@ enum {
 	/** The device supports setting its sample interval, in ms. */
 	SR_CONF_SAMPLE_INTERVAL,
 
+	/** Number of timebases, as related to SR_CONF_TIMEBASE.  */
+	SR_CONF_NUM_TIMEBASE,
+
+	/** Number of vertical divisions, as related to SR_CONF_VDIV.  */
+	SR_CONF_NUM_VDIV,
+
 	/*--- Special stuff -------------------------------------------------*/
 
 	/** Scan options supported by the driver. */