diff --git a/.claude/memory/journal.md b/.claude/memory/journal.md
index e7c232a..bee589a 100644
--- a/.claude/memory/journal.md
+++ b/.claude/memory/journal.md
@@ -108,3 +108,6 @@ Done: copy-mode-vi WheelUp/DownPane rebound `-N 2` (stock 5), live reload OK. Me
 
 ## 2026-10-06 (pm, 7) — tmux ctrl+h/j/k/u in copy-mode
 Done: copy-mode-vi table had stock C-h cursor-left, C-u halfpage-up, C-j copy, so no-prefix pane moves became text nav once scrolled. Four keys rebound select-pane in copy-mode-vi, live reload OK. Merged bugfix/tmux-copy-mode-ctrl-nav → develop (8b6ed6b). Open: deployed ~/.config/tmux/tmux.conf on this Mac predates alt+v/wheel/this fix, `./install.sh` not re-run.
+
+## 2026-10-06 (pm, 8) — tmux drag "syntax error" in claude panes
+Done: MouseDrag1Pane binding had `\"` inside '...' (literal since tmux 3.0); branch for mouse-tracking panes (claude fullscreen, vim mouse=a) failed to parse → "syntax error", no selection. Backslashes dropped, pitfall noted in conf. Deployed to ~/.config/tmux/tmux.conf + source-file, live binding verified (`forwarded-to-app`). Branch bugfix/tmux-drag-syntax-error (31f8400), not merged. Closes the "deployed conf stale" open item.
diff --git a/tmux.conf b/tmux.conf
index a3f7c84..6b76418 100644
--- a/tmux.conf
+++ b/tmux.conf
@@ -166,7 +166,7 @@ bind -T copy-mode-vi WheelUpPane   select-pane \; send-keys -X -N 2 scroll-up
 bind -T copy-mode-vi WheelDownPane select-pane \; send-keys -X -N 2 scroll-down
 bind-key -T copy-mode-vi MouseDown1Pane select-pane -t = \; send-keys -X clear-selection
 bind-key -T copy-mode-vi MouseUp1Pane   select-pane -t = \; send-keys -X cancel
-bind -n MouseDrag1Pane if -Ft= '#{mouse_any_flag}' 'if -Ft= \"#{pane_in_mode}\" \"copy-mode -eM\" \"send-keys -M\"' 'copy-mode -eM'
+bind -n MouseDrag1Pane if -Ft= '#{mouse_any_flag}' 'if -Ft= "#{pane_in_mode}" "copy-mode -eM" "send-keys -M"' 'copy-mode -eM'
 # (note) {{{
 # A plain click (MouseDown then MouseUp, no drag) leaves copy-mode: back to
 #   the prompt, selection dropped. A drag sends MouseDrag/MouseDragEnd instead
@@ -176,6 +176,8 @@ bind -n MouseDrag1Pane if -Ft= '#{mouse_any_flag}' 'if -Ft= \"#{pane_in_mode}\"
 #   MouseDrag1Pane, the only difference is that we use `copy-mode -eM` instead
 #   of `copy-mode -M`, so that WheelDownPane can trigger copy-mode to exit when
 #   copy-mode is entered by MouseDrag1Pane
+# Inner quotes stay plain: `\"` is literal inside '...' since tmux 3.0, and the
+#   mouse-app branch (claude, vim) then dies with "syntax error" on every drag.
 # }}}
 
 bind-key k "split-window -v -b -c '#{pane_current_path}'"