diff --git a/src/buffer.c b/src/buffer.c
index 2f574e0..e8e1a6d 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -372,7 +372,7 @@
 set_bufref(bufref_T *bufref, buf_T *buf)
 {
     bufref->br_buf = buf;
-    bufref->br_fnum = buf->b_fnum;
+    bufref->br_fnum = buf == NULL ? 0 : buf->b_fnum;
     bufref->br_buf_free_count = buf_free_count;
 }
 
diff --git a/src/version.c b/src/version.c
index 59f0d09..b221ce2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    648,
+/**/
     647,
 /**/
     646,