diff --git a/oh-my-zsh.sh b/oh-my-zsh.sh
index b939090e..29b1d3bc 100644
--- a/oh-my-zsh.sh
+++ b/oh-my-zsh.sh
@@ -44,6 +44,11 @@ fi
 # Load all of your custom configurations from custom/
 for config_file ($ZSH/custom/*.zsh) source $config_file
 
+# Compile zcompdump, if modified, to increase startup speed.
+if [ "$HOME/.zcompdump" -nt "$HOME/.zcompdump.zwc" -o ! -e "$HOME/.zcompdump.zwc" ]; then
+  zcompile "$HOME/.zcompdump"
+fi
+
 # Check for updates on initial load...
 if [ "$DISABLE_AUTO_UPDATE" = "true" ]
 then