diff --git a/config/tmux.conf b/config/tmux.conf
index 84e7b12..0cb0a49 100644
--- a/config/tmux.conf
+++ b/config/tmux.conf
@@ -1,2 +1,82 @@
-# run-shell "~/.tmux/verify_tmux_version.sh"
-source-file "~/.tmux/tmux_3.1c.conf"
+# ----------------------------------------------------------------------------
+# Prefix
+# ----------------------------------------------------------------------------
+set -g prefix C-a
+unbind C-b
+bind C-a send-prefix
+bind Tab last-window
+
+# ----------------------------------------------------------------------------
+# General behavior
+# ----------------------------------------------------------------------------
+set-option -g set-titles on
+set -g default-terminal "screen-256color"
+set -g history-limit 10000
+set -sg escape-time 1
+set-option -g base-index 1
+setw -g pane-base-index 1
+setw -g aggressive-resize on
+
+# ----------------------------------------------------------------------------
+# Windows and panes
+# ----------------------------------------------------------------------------
+bind T swap-window -t 1
+bind | split-window -h -c "#{pane_current_path}"
+bind - split-window -v -c "#{pane_current_path}"
+bind c new-window -c "#{pane_current_path}"
+
+bind h select-pane -L
+bind j select-pane -D
+bind k select-pane -U
+bind l select-pane -R
+
+# Smart pane switching with awareness of vim splits
+is_vim='echo "#{pane_current_command}" | grep -iqE "(^|\/)g?(view|n?vim?)(diff)?$"'
+bind -n C-h if-shell "$is_vim" "send-keys C-h" "select-pane -L"
+bind -n C-j if-shell "$is_vim" "send-keys C-j" "select-pane -D"
+bind -n C-k if-shell "$is_vim" "send-keys C-k" "select-pane -U"
+bind -n C-l if-shell "$is_vim" "send-keys C-l" "select-pane -R"
+bind -n 'C-\' if-shell "$is_vim" "send-keys 'C-\\'" "select-pane -l"
+
+bind -r C-h select-window -t :-
+bind -r C-l select-window -t :+
+
+bind a setw synchronize-panes
+
+# ----------------------------------------------------------------------------
+# Copy mode and mouse
+# ----------------------------------------------------------------------------
+setw -g mode-keys vi
+set-option -g -q mouse on
+
+bind y run 'tmux save-buffer - | reattach-to-user-namespace pbcopy'
+bind C-y run 'tmux save-buffer - | reattach-to-user-namespace pbcopy'
+
+# tmux renamed the copy-mode key table (vi-copy -> copy-mode-vi) and changed
+# bind-key's table flag (-t -> -T) in 2.4. Source the file matching the
+# running tmux so old tmux never parses syntax it doesn't understand.
+if-shell "tmux -V | awk '{print $2}' | awk -F. '{if ($1*1000+$2 < 2004) exit 0; else exit 1}'" 'source-file ~/.tmux/legacy.conf' 'source-file ~/.tmux/modern.conf'
+
+# ----------------------------------------------------------------------------
+# Misc bindings
+# ----------------------------------------------------------------------------
+bind-key C run-shell "cal $(date +%Y)"
+bind r source-file ~/.tmux.conf \; display "Reloaded config"
+
+# ----------------------------------------------------------------------------
+# Powerline (guarded so machines without it don't error on load)
+# ----------------------------------------------------------------------------
+run-shell "command -v powerline-daemon >/dev/null 2>&1 && powerline-daemon -q; true"
+run-shell "command -v powerline-config >/dev/null 2>&1 && powerline-config tmux setup; true"
+
+# ----------------------------------------------------------------------------
+# Plugins (TPM)
+# ----------------------------------------------------------------------------
+set -g @plugin 'tmux-plugins/tpm'
+set -g @plugin 'tmux-plugins/tmux-sensible'
+
+# Local overrides
+if-shell "[ -f ~/.tmux_local.conf ]" 'source ~/.tmux_local.conf'
+
+# Initialize TPM (must be the last line)
+run '~/.tmux/plugins/tpm/tpm'
diff --git a/config/tmux/legacy.conf b/config/tmux/legacy.conf
new file mode 100644
index 0000000..796ad2a
--- /dev/null
+++ b/config/tmux/legacy.conf
@@ -0,0 +1,16 @@
+# tmux < 2.4 copy-mode key table (vi-copy, old -t flag) and mouse-wheel/
+# PageUp passthrough. Sourced conditionally from tmux.conf; see
+# tmux/modern.conf for tmux >= 2.4.
+
+bind-key -t vi-copy PPage page-up
+bind-key -t vi-copy NPage page-down
+bind-key -t vi-copy WheelUpPane halfpage-up
+bind-key -t vi-copy WheelDownPane halfpage-down
+bind-key -t vi-copy v begin-selection
+bind-key -t vi-copy y copy-pipe "reattach-to-user-namespace pbcopy"
+unbind-key -t vi-copy Enter
+bind-key -t vi-copy Enter copy-pipe "reattach-to-user-namespace pbcopy"
+
+bind-key -n PPage if-shell -F "#{alternate_on}" "send-keys PPage" "copy-mode -e; send-keys PPage"
+bind-key -n WheelUpPane if-shell -F -t = "#{alternate_on}" "send-keys -M" "select-pane -t =; copy-mode -e; send-keys -M"
+bind-key -n WheelDownPane if-shell -F -t = "#{alternate_on}" "send-keys -M" "select-pane -t =; send-keys -M"
diff --git a/config/tmux/tmux_3.1c.conf b/config/tmux/modern.conf
similarity index 53%
rename from config/tmux/tmux_3.1c.conf
rename to config/tmux/modern.conf
index e1f37b6..a188ce8 100644
--- a/config/tmux/tmux_3.1c.conf
+++ b/config/tmux/modern.conf
@@ -1,42 +1,17 @@
-# PREFIX | splits horizontally and PREFIX - splits vertically
-bind | split-window -h -c "#{pane_current_path}"
-bind - split-window -v -c "#{pane_current_path}"
+# tmux >= 2.4 copy-mode key table and mouse-wheel/PageUp passthrough.
+# Sourced conditionally from tmux.conf; see tmux/legacy.conf for older tmux.
 
-# open new window with pwd
-bind c new-window -c "#{pane_current_path}"
-
-# use vim keybindings in copy mode
-setw -g mode-keys vi
-
-# Copy Mode
 bind-key -T copy-mode-vi PPage send-keys -X page-up
 bind-key -T copy-mode-vi NPage send-keys -X page-down
-
-# Mouse Wheel
 bind-key -T copy-mode-vi WheelUpPane send-keys -X halfpage-up
 bind-key -T copy-mode-vi WheelDownPane send-keys -X halfpage-down
-
-# v selection
 bind-key -T copy-mode-vi v send-keys -X begin-selection
 bind-key -T copy-mode-vi y send-keys -X copy-pipe "reattach-to-user-namespace pbcopy"
-
-# make enter use copy pipe
-unbind -T copy-mode-vi Enter
+unbind-key -T copy-mode-vi Enter
 bind-key -T copy-mode-vi Enter send-keys -X copy-pipe "reattach-to-user-namespace pbcopy"
 
-set-option -g -q mouse on
-set-option -g -q mouse-resize-pane on
-set-option -g -q mouse-select-pane on
-set-option -g -q mouse-select-window on
-
-# Enable middle click in urxvt
-set-option -ga terminal-override ',rxvt-uni*:XT:Ms=\E]52;%p1%s;%p2%s\007'
-
-# Copy Mode
+# Let mouse wheel / PageUp pass through to apps using the alternate screen
+# (vim, less, etc.) instead of always entering copy-mode
 bind-key -T root PPage if-shell -F "#{alternate_on}" "send-keys PPage" "copy-mode -e; send-keys PPage"
-
-# Mouse Wheel
 bind-key -T root WheelUpPane if-shell -F -t = "#{alternate_on}" "send-keys -M" "select-pane -t =; copy-mode -e; send-keys -M"
 bind-key -T root WheelDownPane if-shell -F -t = "#{alternate_on}" "send-keys -M" "select-pane -t =; send-keys -M"
-
-source ~/.tmux/tmux_shared.conf
diff --git a/config/tmux/tmux_1.9_down.conf b/config/tmux/tmux_1.9_down.conf
deleted file mode 100644
index 16840c0..0000000
--- a/config/tmux/tmux_1.9_down.conf
+++ /dev/null
@@ -1,37 +0,0 @@
-# PREFIX | splits horizontally and PREFIX - splits vertically
-bind | split-window -h
-bind - split-window -v
-
-# mouse support
-set -g mode-mouse on # scrolling
-set -g mouse-select-pane on # clicking into panes
-set -g mouse-resize-pane on # resizing panes
-set -g mouse-select-window on # select windows
-
-# toggle mouse support
-bind m \
-    set -g mode-mouse on \;\
-    set -g mouse-resize-pane on \;\
-    set -g mouse-select-pane on \;\
-    set -g mouse-select-window on \;\
-    display 'Mouse: ON'
-
-bind M \
-    set -g mode-mouse off \;\
-    set -g mouse-resize-pane off \;\
-    set -g mouse-select-pane off \;\
-    set -g mouse-select-window off \;\
-    display 'Mouse: OFF'
-
-# ----------------------
-# set some pretty colors
-# ----------------------
-# set pane colors - hilight the active pane
-# set-option -g pane-border-fg colour235 #base02
-# set-option -g pane-active-border-fg colour240 #base01
-
-# # colorize messages in the command line
-# set-option -g message-bg black #base02
-# set-option -g message-fg brightred #orange
-
-source "$HOME/.tmux/tmux_shared.conf"
diff --git a/config/tmux/tmux_1.9_to_2.1.conf b/config/tmux/tmux_1.9_to_2.1.conf
deleted file mode 100644
index c4063c7..0000000
--- a/config/tmux/tmux_1.9_to_2.1.conf
+++ /dev/null
@@ -1,2 +0,0 @@
-
-source "$HOME/.tmux/tmux_shared.conf"
diff --git a/config/tmux/tmux_2.1_to_2.5.conf b/config/tmux/tmux_2.1_to_2.5.conf
deleted file mode 100644
index 37264ec..0000000
--- a/config/tmux/tmux_2.1_to_2.5.conf
+++ /dev/null
@@ -1,48 +0,0 @@
-# PREFIX | splits horizontally and PREFIX - splits vertically
-bind | split-window -h -c "#{pane_current_path}"
-bind - split-window -v -c "#{pane_current_path}"
-
-# open new window with pwd
-bind c new-window -c "#{pane_current_path}"
-
-# PREFIX T makes current window index 1
-bind T swap-window -t 1
-
-# use vim movement for panes
-bind h select-pane -L
-bind j select-pane -D
-bind k select-pane -U
-bind l select-pane -R
-
-# mouse support
-set-option -g -q mouse on
-
-# Copy Mode
-bind-key -t root PPage if-shell -F "#{alternate_on}" "send-keys PPage" "copy-mode -e; send-keys PPage"
-bind-key -t vi-copy PPage page-up
-bind-key -t vi-copy NPage page-down
-# Mouse Wheel
-bind-key -t root WheelUpPane if-shell -F -t = "#{alternate_on}" "send-keys -M" "select-pane -t =; copy-mode -e; send-keys -M"
-bind-key -t root WheelDownPane if-shell -F -t = "#{alternate_on}" "send-keys -M" "select-pane -t =; send-keys -M"
-bind-key -t vi-copy WheelUpPane halfpage-up
-bind-key -t vi-copy WheelDownPane halfpage-down
-
-# Make sure the client is always using the correct environment
-# eval $(tmux switch-client \; show-environment -s)
-
-# Copy/Paste
-#
-# provide access to clipboard
-# set-option -g default-command "reattach-to-user-namespace -l zsh"
-# set-window-option -g automatic-rename on
-
-# use vim keybindings in copy mode
-setw -g mode-keys vi
-
-# v selection
-bind-key -t vi-copy v begin-selection
-bind-key -t vi-copy y copy-pipe "reattach-to-user-namespace pbcopy"
-
-# make enter use copy pipe
-unbind -t vi-copy Enter
-bind-key -t vi-copy Enter copy-pipe "reattach-to-user-namespace pbcopy"
diff --git a/config/tmux/tmux_2.5_up.conf b/config/tmux/tmux_2.5_up.conf
deleted file mode 100644
index e1f37b6..0000000
--- a/config/tmux/tmux_2.5_up.conf
+++ /dev/null
@@ -1,42 +0,0 @@
-# PREFIX | splits horizontally and PREFIX - splits vertically
-bind | split-window -h -c "#{pane_current_path}"
-bind - split-window -v -c "#{pane_current_path}"
-
-# open new window with pwd
-bind c new-window -c "#{pane_current_path}"
-
-# use vim keybindings in copy mode
-setw -g mode-keys vi
-
-# Copy Mode
-bind-key -T copy-mode-vi PPage send-keys -X page-up
-bind-key -T copy-mode-vi NPage send-keys -X page-down
-
-# Mouse Wheel
-bind-key -T copy-mode-vi WheelUpPane send-keys -X halfpage-up
-bind-key -T copy-mode-vi WheelDownPane send-keys -X halfpage-down
-
-# v selection
-bind-key -T copy-mode-vi v send-keys -X begin-selection
-bind-key -T copy-mode-vi y send-keys -X copy-pipe "reattach-to-user-namespace pbcopy"
-
-# make enter use copy pipe
-unbind -T copy-mode-vi Enter
-bind-key -T copy-mode-vi Enter send-keys -X copy-pipe "reattach-to-user-namespace pbcopy"
-
-set-option -g -q mouse on
-set-option -g -q mouse-resize-pane on
-set-option -g -q mouse-select-pane on
-set-option -g -q mouse-select-window on
-
-# Enable middle click in urxvt
-set-option -ga terminal-override ',rxvt-uni*:XT:Ms=\E]52;%p1%s;%p2%s\007'
-
-# Copy Mode
-bind-key -T root PPage if-shell -F "#{alternate_on}" "send-keys PPage" "copy-mode -e; send-keys PPage"
-
-# Mouse Wheel
-bind-key -T root WheelUpPane if-shell -F -t = "#{alternate_on}" "send-keys -M" "select-pane -t =; copy-mode -e; send-keys -M"
-bind-key -T root WheelDownPane if-shell -F -t = "#{alternate_on}" "send-keys -M" "select-pane -t =; send-keys -M"
-
-source ~/.tmux/tmux_shared.conf
diff --git a/config/tmux/tmux_shared.conf b/config/tmux/tmux_shared.conf
deleted file mode 100644
index 0ac08f8..0000000
--- a/config/tmux/tmux_shared.conf
+++ /dev/null
@@ -1,110 +0,0 @@
-# use UTF8
-# set -g utf8
-# set-window-option -g utf8 on
-
-# 256 color mode
-set -g default-terminal "screen-256color"
-# set-option -sa terminal-overrides ',screen*:RGB'
-# set-option -ga terminal-overrides ',screen*:Tc'
-# set-option -sa terminal-overrides ',xterm*:RGB'
-# set-option -ga terminal-overrides ',xterm*:Tc'
-# set-option -sa terminal-overrides ',tmux*:RGB'
-# set-option -ga terminal-overrides ',tmux*:Tc'
-# set-option -sa terminal-overrides ',rxvt*:RGB'
-# set-option -ga terminal-overrides ',rxvt*:Tc'
-
-# Properly handle ssh agent forwarding when reconnecting to session
-# set-environment -g 'SSH_AUTH_SOCK' ~/.ssh/ssh_auth_sock
-
-set-option -g set-titles on
-# Tmux attach will create a new session if one doesn't exist
-# new-session -n $HOST
-
-# set scrollback history
-set -g history-limit 10000
-
-# set Ctrl-a as prefix and unbind Ctrl-b
-set -g prefix C-a
-unbind C-b
-
-# last active window
-# bind-key C-a last-window
-bind Tab last-window
-
-# pass prefix through to application
-bind C-a send-prefix
-
-# don't constrain size unless smaller client looking at window
-setw -g aggressive-resize on
-
-# set command delay
-set -sg escape-time 1
-
-# set base index to 1 rather than 0
-set-option -g base-index 1
-setw -g pane-base-index 1
-
-# use PREFIX-r to reload config
-bind r source-file ~/.tmux/tmux_shared.conf \; display "Reloaded config"
-
-# PREFIX T makes current window index 1
-bind T swap-window -t 1
-
-# use vim movement for panes
-bind h select-pane -L
-bind j select-pane -D
-bind k select-pane -U
-bind l select-pane -R
-
-# Smart pane switching with awareness of vim splits
-is_vim='echo "#{pane_current_command}" | grep -iqE "(^|\/)g?(view|n?vim?)(diff)?$"'
-bind -n C-h if-shell "$is_vim" "send-keys C-h" "select-pane -L"
-bind -n C-j if-shell "$is_vim" "send-keys C-j" "select-pane -D"
-bind -n C-k if-shell "$is_vim" "send-keys C-k" "select-pane -U"
-bind -n C-l if-shell "$is_vim" "send-keys C-l" "select-pane -R"
-bind -n 'C-\' if-shell "$is_vim" "send-keys 'C-\\'" "select-pane -l"
-
-# bind C-h and C-l to cycle through panes
-bind -r C-h select-window -t :-
-bind -r C-l select-window -t :+
-
-# Synchonize keyboard input across panes
-bind a setw synchronize-panes
-
-# open calendar
-bind-key C run-shell "cal $(date +%Y)"
-
-# Make sure the client is always using the correct environment
-# eval $(tmux switch-client \; show-environment -s)
-
-bind y run 'tmux save-buffer - | reattach-to-user-namespace pbcopy '
-bind C-y run 'tmux save-buffer - | reattach-to-user-namespace pbcopy '1
-
-# ----------------------
-# set some pretty colors
-# ----------------------
-# set pane colors - hilight the active pane
-# set-option -g pane-border-fg colour235 #base02
-# set-option -g pane-active-border-fg colour240 #base01
-
-# Show active pane
-# set-window-option -g window-style 'bg=#181818'
-# set-window-option -g window-active-style 'bg=black'
-# set-window-option -g pane-active-border-style ''
-# set-window-option -g pane-active-border-style 'fg=#181818'
-
-# colorize messages in the command line
-# set-option -g message-bg black #base02
-# set-option -g message-fg brightred #orange
-
-# Powerline
-run-shell "powerline-daemon -q"
-run-shell "powerline-config tmux setup"
-# source-file $POWERLINE_ROOT/bindings/tmux/powerline.conf
-
-# Tmux plugins
-set -g @plugin 'tmux-plugins/tpm'
-set -g @plugin 'tmux-plugins/tmux-sensible'
-
-# Local overrides
-if-shell "[ -f ~/.tmux_local.conf ]" 'source ~/.tmux_local.conf'
diff --git a/config/tmux/verify_tmux_version.sh b/config/tmux/verify_tmux_version.sh
deleted file mode 100755
index 34fc96b..0000000
--- a/config/tmux/verify_tmux_version.sh
+++ /dev/null
@@ -1,27 +0,0 @@
-#!/bin/bash
-
-verify_tmux_version() {
-    tmux_home=~/.tmux
-    tmux_version="$(tmux -V | cut -c 6-)"
-
-    # This is necessary because 3.1c gives a syntax error in bc
-    # TODO Fix this it will break with the next tmux version
-    if [[ $tmux_version -eq "3.1c"]] ; then
-        source-file $tmux_home/tmux_3.1c.conf
-        exit
-    if [[ $(echo "$tmux_version >= 2.5" | bc) -eq 1 ]] ; then
-        source-file $tmux_home/tmux_3.1c.conf
-        exit
-    elif [[ $(echo "$tmux_version >= 2.1" | bc) -eq 1 ]] ; then
-        source-file $tmux_home/tmux_2.1_to_2.5.conf
-        exit
-    elif [[ $(echo "$tmux_version >= 1.9" | bc) -eq 1 ]] ; then
-        source-file $tmux_home/tmux_1.9_to_2.1.conf
-        exit
-    else
-        source-file $tmux_home/tmux_1.9_down.conf
-        exit
-    fi
-}
-
-verify_tmux_version