diff --git a/metrics/expvar/expvar.go b/metrics/expvar/expvar.go
index ba8624b..eba74c9 100644
--- a/metrics/expvar/expvar.go
+++ b/metrics/expvar/expvar.go
@@ -42,20 +42,20 @@
 func (c *counter) Add(delta uint64) { c.v.Add(int64(delta)) }
 
 type gauge struct {
-	v *expvar.Int
+	v *expvar.Float
 }
 
 // NewGauge returns a new Gauge backed by an expvar with the given name.
 // Fields are ignored.
 func NewGauge(name string) metrics.Gauge {
-	return &gauge{expvar.NewInt(name)}
+	return &gauge{expvar.NewFloat(name)}
 }
 
 func (g *gauge) With(metrics.Field) metrics.Gauge { return g }
 
-func (g *gauge) Add(delta int64) { g.v.Add(delta) }
+func (g *gauge) Add(delta float64) { g.v.Add(delta) }
 
-func (g *gauge) Set(value int64) { g.v.Set(value) }
+func (g *gauge) Set(value float64) { g.v.Set(value) }
 
 type histogram struct {
 	mu   sync.Mutex
@@ -100,7 +100,7 @@
 	}
 
 	for q, gauge := range h.gauges {
-		gauge.Set(h.hist.Current.ValueAtQuantile(float64(q)))
+		gauge.Set(float64(h.hist.Current.ValueAtQuantile(float64(q))))
 	}
 }
 
diff --git a/metrics/metrics.go b/metrics/metrics.go
index e76660f..49e93d3 100644
--- a/metrics/metrics.go
+++ b/metrics/metrics.go
@@ -14,11 +14,11 @@
 }
 
 // Gauge captures instantaneous measurements of something using signed, 64-bit
-// integers. The value does not need to be monotonic.
+// floats. The value does not need to be monotonic.
 type Gauge interface {
 	With(Field) Gauge
-	Set(value int64)
-	Add(delta int64)
+	Set(value float64)
+	Add(delta float64)
 }
 
 // Histogram tracks the distribution of a stream of values (e.g. the number of
diff --git a/metrics/multi.go b/metrics/multi.go
index 66c8074..b3990bd 100644
--- a/metrics/multi.go
+++ b/metrics/multi.go
@@ -44,13 +44,13 @@
 	return next
 }
 
-func (g multiGauge) Set(value int64) {
+func (g multiGauge) Set(value float64) {
 	for _, gauge := range g {
 		gauge.Set(value)
 	}
 }
 
-func (g multiGauge) Add(delta int64) {
+func (g multiGauge) Add(delta float64) {
 	for _, gauge := range g {
 		gauge.Add(delta)
 	}
diff --git a/metrics/prometheus/prometheus.go b/metrics/prometheus/prometheus.go
index 7187413..87ef4eb 100644
--- a/metrics/prometheus/prometheus.go
+++ b/metrics/prometheus/prometheus.go
@@ -103,12 +103,12 @@
 	}
 }
 
-func (g prometheusGauge) Set(value int64) {
-	g.GaugeVec.With(prometheus.Labels(g.Pairs)).Set(float64(value))
+func (g prometheusGauge) Set(value float64) {
+	g.GaugeVec.With(prometheus.Labels(g.Pairs)).Set(value)
 }
 
-func (g prometheusGauge) Add(delta int64) {
-	g.GaugeVec.With(prometheus.Labels(g.Pairs)).Add(float64(delta))
+func (g prometheusGauge) Add(delta float64) {
+	g.GaugeVec.With(prometheus.Labels(g.Pairs)).Add(delta)
 }
 
 type prometheusHistogram struct {
diff --git a/metrics/statsd/statsd.go b/metrics/statsd/statsd.go
index 5f091fa..8771a8e 100644
--- a/metrics/statsd/statsd.go
+++ b/metrics/statsd/statsd.go
@@ -61,17 +61,17 @@
 
 func (g statsdGauge) With(metrics.Field) metrics.Gauge { return g }
 
-func (g statsdGauge) Add(delta int64) {
+func (g statsdGauge) Add(delta float64) {
 	// https://github.com/etsy/statsd/blob/master/docs/metric_types.md#gauges
 	sign := "+"
 	if delta < 0 {
 		sign, delta = "-", -delta
 	}
-	g <- fmt.Sprintf("%s%d|g", sign, delta)
+	g <- fmt.Sprintf("%s%f|g", sign, delta)
 }
 
-func (g statsdGauge) Set(value int64) {
-	g <- fmt.Sprintf("%d|g", value)
+func (g statsdGauge) Set(value float64) {
+	g <- fmt.Sprintf("%f|g", value)
 }
 
 type statsdHistogram chan string
diff --git a/metrics/statsd/statsd_test.go b/metrics/statsd/statsd_test.go
index d0a2ff0..46a2380 100644
--- a/metrics/statsd/statsd_test.go
+++ b/metrics/statsd/statsd_test.go
@@ -42,7 +42,7 @@
 	runtime.Gosched() // yield to buffer write
 	ch <- time.Now()  // signal flush
 	runtime.Gosched() // yield to flush
-	if want, have := "test_statsd_gauge:+1|g\n", buf.String(); want != have {
+	if want, have := "test_statsd_gauge:+1.000000|g\n", buf.String(); want != have {
 		t.Errorf("want %q, have %q", want, have)
 	}
 
@@ -52,7 +52,7 @@
 	runtime.Gosched()
 	ch <- time.Now()
 	runtime.Gosched()
-	if want, have := "test_statsd_gauge:-2|g\n", buf.String(); want != have {
+	if want, have := "test_statsd_gauge:-2.000000|g\n", buf.String(); want != have {
 		t.Errorf("want %q, have %q", want, have)
 	}
 
@@ -62,7 +62,7 @@
 	runtime.Gosched()
 	ch <- time.Now()
 	runtime.Gosched()
-	if want, have := "test_statsd_gauge:3|g\n", buf.String(); want != have {
+	if want, have := "test_statsd_gauge:3.000000|g\n", buf.String(); want != have {
 		t.Errorf("want %q, have %q", want, have)
 	}
 }