diff --git a/serve.go b/serve.go
index 0a930c3..04c245b 100644
--- a/serve.go
+++ b/serve.go
@@ -24,6 +24,7 @@ func Serve() {
 		flag.Parse()
 	}
 
+	DefaultMux.Compile()
 	// Install our handler at the root of the standard net/http default mux.
 	// This allows packages like expvar to continue working as expected.
 	http.Handle("/", DefaultMux)
diff --git a/serve_appengine.go b/serve_appengine.go
index edf9a2d..2d39665 100644
--- a/serve_appengine.go
+++ b/serve_appengine.go
@@ -6,6 +6,7 @@ import "net/http"
 
 // Serve starts Goji using reasonable defaults.
 func Serve() {
+	DefaultMux.Compile()
 	// Install our handler at the root of the standard net/http default mux.
 	// This is required for App Engine, and also allows packages like expvar
 	// to continue working as expected.