diff --git a/modules/ruby/init.zsh b/modules/ruby/init.zsh
index 174d185..fd707d0 100644
--- a/modules/ruby/init.zsh
+++ b/modules/ruby/init.zsh
@@ -28,6 +28,9 @@ elif (( $+commands[chruby-exec] )); then
   source "${commands[chruby-exec]:h:h}/share/chruby/chruby.sh"
   if zstyle -t ':prezto:module:ruby:chruby' auto-switch; then
     source "${commands[chruby-exec]:h:h}/share/chruby/auto.sh"
+
+    # If a default Ruby is set, switch to it.
+    chruby_auto
   fi
 
 # Prepend local gems bin directories to PATH.