1 files changed, 5 insertions, 0 deletions

diff --git a/src/xterm.c b/src/xterm.c
index e04b04ea651..8145689d416 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -4566,6 +4566,11 @@ XTread_socket (sd, bufp, numchars, expected)
                   {
                     dpyinfo->grabbed |= (1 << event.xbutton.button);
                     last_mouse_frame = f;
+                    /* Ignore any mouse motion that happened
+                       before this event; any subsequent mouse-movement
+                       Emacs events should reflect only motion after
+                       the ButtonPress.  */
+                    f->mouse_moved = 0;
                   }
                 else
                   {