diff --git a/android/metrics.go b/android/metrics.go
index 1580f82..ecda026 100644
--- a/android/metrics.go
+++ b/android/metrics.go
@@ -32,8 +32,13 @@
 	Variants int
 }
 
-func ReadSoongMetrics(config Config) SoongMetrics {
-	return config.Get(soongMetricsOnceKey).(SoongMetrics)
+func readSoongMetrics(config Config) (SoongMetrics, bool) {
+	soongMetrics, ok := config.Peek(soongMetricsOnceKey)
+	if ok {
+		return soongMetrics.(SoongMetrics), true
+	} else {
+		return SoongMetrics{}, false
+	}
 }
 
 func init() {
@@ -60,9 +65,11 @@
 func collectMetrics(config Config, eventHandler metrics.EventHandler) *soong_metrics_proto.SoongBuildMetrics {
 	metrics := &soong_metrics_proto.SoongBuildMetrics{}
 
-	soongMetrics := ReadSoongMetrics(config)
-	metrics.Modules = proto.Uint32(uint32(soongMetrics.Modules))
-	metrics.Variants = proto.Uint32(uint32(soongMetrics.Variants))
+	soongMetrics, ok := readSoongMetrics(config)
+	if ok {
+		metrics.Modules = proto.Uint32(uint32(soongMetrics.Modules))
+		metrics.Variants = proto.Uint32(uint32(soongMetrics.Variants))
+	}
 
 	memStats := runtime.MemStats{}
 	runtime.ReadMemStats(&memStats)
diff --git a/android/onceper.go b/android/onceper.go
index 481cdea..fa415d1 100644
--- a/android/onceper.go
+++ b/android/onceper.go
@@ -79,6 +79,17 @@
 	return once.maybeWaitFor(key, v)
 }
 
+// Peek returns the value previously computed with Once for a given key.  If Once has not
+// been called for the given key Peek will return ok == false.
+func (once *OncePer) Peek(key OnceKey) (interface{}, bool) {
+	v, ok := once.values.Load(key)
+	if !ok {
+		return nil, false
+	}
+
+	return once.maybeWaitFor(key, v), true
+}
+
 // OnceStringSlice is the same as Once, but returns the value cast to a []string
 func (once *OncePer) OnceStringSlice(key OnceKey, value func() []string) []string {
 	return once.Once(key, func() interface{} { return value() }).([]string)