diff --git a/dot_tmux.conf b/dot_tmux.conf
index 4e718cd..b04ac76 100644
--- a/dot_tmux.conf
+++ b/dot_tmux.conf
@@ -64,7 +64,8 @@ bind -T copy-mode-vi y send -X copy-selection-and-cancel
 bind -T copy-mode-vi MouseDragEnd1Pane send -X copy-selection-and-cancel
 
 # OSC 52 clipboard integration (for SSH remote copy)
-set -s set-clipboard on
+# Use 'external' to forward OSC 52 to outer terminal (required for nested tmux over SSH)
+set -s set-clipboard external
 set -g allow-passthrough on
 
 # -----------------------------------------------------------------------------