1 files changed, 2 insertions, 1 deletions

diff --git a/src/process.c b/src/process.c
index e885f771139..8419b1e88ca 100644
--- a/src/process.c
+++ b/src/process.c
@@ -1279,7 +1279,8 @@ static void
 update_process_mark (struct Lisp_Process *p)
 {
   Lisp_Object buffer = p->buffer;
-  if (BUFFERP (buffer))
+  if (BUFFERP (buffer)
+      && XMARKER (p->mark)->buffer != XBUFFER (buffer))
     set_marker_both (p->mark, buffer,
                      BUF_ZV (XBUFFER (buffer)),
                      BUF_ZV_BYTE (XBUFFER (buffer)));