diff --git a/collector.v b/collector.v
index 149095b..39c2b42 100644
--- a/collector.v
+++ b/collector.v
@@ -6,6 +6,18 @@ mut:
 	data u64
 }
 
+struct Gauge {
+	metric Metric
+pub mut:
+	data f64
+}
+
+struct Histogram {
+	metric Metric
+pub mut:
+	buckets []f64
+}
+
 struct FloatSeries {
 	metric Metric
 pub mut:
@@ -17,14 +29,14 @@ struct DefaultCollector {
 mut:
 	counters   shared map[string]&Counter
 	histograms shared map[string]&FloatSeries
-	gauges     shared map[string]&FloatSeries
+	gauges     shared map[string]&Gauge
 }
 
 pub fn new_default_collector() &DefaultCollector {
 	return &DefaultCollector{
 		counters: map[string]&Counter{}
 		histograms: map[string]&FloatSeries{}
-		gauges: map[string]&FloatSeries{}
+		gauges: map[string]&Gauge{}
 	}
 }
 
@@ -109,9 +121,9 @@ pub fn (c &DefaultCollector) histogram_get(metric Metric) ?[]f64 {
 pub fn (mut c DefaultCollector) gauge_add(value f64, metric Metric) {
 	lock c.gauges {
 		mut entry := c.gauges[metric.str()] or {
-			gauge := &FloatSeries{
+			gauge := &Gauge{
 				metric: metric
-				data: [0.0]
+				data: 0.0
 			}
 
 			c.gauges[metric.str()] = gauge
@@ -119,16 +131,16 @@ pub fn (mut c DefaultCollector) gauge_add(value f64, metric Metric) {
 			gauge
 		}
 
-		entry.data[0] += value
+		entry.data += value
 	}
 }
 
 pub fn (mut c DefaultCollector) gauge_sub(value f64, metric Metric) {
 	lock c.gauges {
 		mut entry := c.gauges[metric.str()] or {
-			gauge := &FloatSeries{
+			gauge := &Gauge{
 				metric: metric
-				data: [0.0]
+				data: 0.0
 			}
 
 			c.gauges[metric.str()] = gauge
@@ -136,16 +148,16 @@ pub fn (mut c DefaultCollector) gauge_sub(value f64, metric Metric) {
 			gauge
 		}
 
-		entry.data[0] -= value
+		entry.data -= value
 	}
 }
 
 pub fn (mut c DefaultCollector) gauge_set(value f64, metric Metric) {
 	lock c.gauges {
 		mut entry := c.gauges[metric.str()] or {
-			gauge := &FloatSeries{
+			gauge := &Gauge{
 				metric: metric
-				data: [0.0]
+				data: 0.0
 			}
 
 			c.gauges[metric.str()] = gauge
@@ -153,7 +165,7 @@ pub fn (mut c DefaultCollector) gauge_set(value f64, metric Metric) {
 			gauge
 		}
 
-		entry.data[0] = value
+		entry.data = value
 	}
 }
 
@@ -161,7 +173,7 @@ pub fn (c &DefaultCollector) gauge_get(metric Metric) ?f64 {
 	return rlock c.gauges {
 		entry := c.gauges[metric.str()] or { return none }
 
-		entry.data[0]
+		entry.data
 	}
 }