diff --git a/tmux.conf b/tmux.conf
index e38a1de..7523abe 100644
--- a/tmux.conf
+++ b/tmux.conf
@@ -41,9 +41,10 @@ bind -n M-Up select-pane -U
 bind -n M-Down select-pane -D
 
 # enable vi mode keys
-set-window-option -g mode-keys vi
-bind -t vi-copy 'v' begin-selection
-bind -t vi-copy 'y' copy-selection
+bind-key -T copy-mode-vi 'v' send -X begin-selection
+bind-key -T copy-mode-vi 'y' send -X copy-selection
+bind-key -T copy-mode-vi 'Space' send -X halfpage-down
+bind-key -T copy-mode-vi 'Bspace' send -X halfpage-up
 
 # set default terminal mode to 256 colors
 set -g default-terminal "screen-256color"