diff --git a/internal/metrics/service.go b/internal/metrics/service.go
index 00573a5..f6126dd 100644
--- a/internal/metrics/service.go
+++ b/internal/metrics/service.go
@@ -145,7 +145,10 @@
 //
 // The resource will be in StackDrvier's gae_instance type.
 func GAEResource(ctx context.Context) (*MonitoredResource, error) {
-	if !appengine.IsAppEngine() {
+	// appengine.IsAppEngine is confusingly false as we're using a custom
+	// container and building without the appenginevm build constraint.
+	// Check metadata.OnGCE instead.
+	if !metadata.OnGCE() {
 		return nil, fmt.Errorf("not running on appengine")
 	}
 	projID, err := metadata.ProjectID()
diff --git a/main.go b/main.go
index af9774e..ed59695 100644
--- a/main.go
+++ b/main.go
@@ -13,6 +13,7 @@
 
 	"cloud.google.com/go/compute/metadata"
 	"cloud.google.com/go/datastore"
+	"golang.org/x/playground/internal/metrics"
 )
 
 var log = newStdLogger()
@@ -44,7 +45,7 @@
 		}
 		s.log = log
 		return nil
-	})
+	}, enableMetrics)
 	if err != nil {
 		log.Fatalf("Error creating server: %v", err)
 	}
@@ -71,6 +72,21 @@
 	log.Fatalf("Error listening on :%v: %v", port, http.ListenAndServe(":"+port, s))
 }
 
+func enableMetrics(s *server) error {
+	gr, err := metrics.GAEResource(context.Background())
+	if err != nil {
+		s.log.Printf("metrics.GAEResource() = _, %q", err)
+	}
+	ms, err := metrics.NewService(gr, views)
+	if err != nil {
+		s.log.Printf("Failed to initialize metrics: metrics.NewService() = _, %q. (not on GCP?)", err)
+	}
+	if ms != nil && !metadata.OnGCE() {
+		s.mux.Handle("/metrics", ms)
+	}
+	return nil
+}
+
 func projectID() string {
 	id, err := metadata.ProjectID()
 	if err != nil && os.Getenv("GAE_INSTANCE") != "" {
diff --git a/server.go b/server.go
index 8b82d23..8352c51 100644
--- a/server.go
+++ b/server.go
@@ -5,15 +5,12 @@
 package main
 
 import (
-	"context"
 	"fmt"
 	"net/http"
 	"os"
 	"strings"
 	"time"
 
-	"cloud.google.com/go/compute/metadata"
-	"golang.org/x/playground/internal/metrics"
 	"golang.org/x/tools/godoc/static"
 )
 
@@ -46,17 +43,6 @@
 			s.modtime = fi.ModTime()
 		}
 	}
-	gr, err := metrics.GAEResource(context.Background())
-	if err != nil {
-		s.log.Printf("metrics.GaeService() = _, %q", err)
-	}
-	ms, err := metrics.NewService(gr, views)
-	if err != nil {
-		s.log.Printf("Failed to initialize metrics: metrics.NewService() = _, %q. (not on GCP?)", err)
-	}
-	if ms != nil && !metadata.OnGCE() {
-		s.mux.Handle("/statusz", ms)
-	}
 	s.init()
 	return s, nil
 }