diff --git a/setup-scripts/tmux.conf b/setup-scripts/tmux.conf
index 0314d36f..043bab9f 100644
--- a/setup-scripts/tmux.conf
+++ b/setup-scripts/tmux.conf
@@ -14,3 +14,5 @@ bind r source-file ~/.tmux.conf
 
 set -g visual-activity off
 set -g mouse on
+# This copies highlighted text.
+set -g mouse-select-window on