diff --git a/reference.c b/reference.c
index eda04bd..10192ea 100644
--- a/reference.c
+++ b/reference.c
@@ -168,6 +168,7 @@ handle_slew(struct timespec *raw,
 
   if (change_type == LCL_ChangeUnknownStep) {
     last_ref_update = 0.0;
+    REF_SetUnsynchronised();
   }
 
   /* When the clock was stepped, check if that doesn't change our leap status
diff --git a/sources.c b/sources.c
index 2e6f45e..b440d9d 100644
--- a/sources.c
+++ b/sources.c
@@ -1128,7 +1128,7 @@ slew_sources(struct timespec *raw, struct timespec *cooked, double dfreq,
   }
 
   if (change_type == LCL_ChangeUnknownStep) {
-    /* After resetting no source is selectable, set reference unsynchronised */
+    /* Update selection status */
     SRC_SelectSource(NULL);
   }
 }