diff --git a/metrics.v b/metrics.v
index 6fdc534..1ecd33c 100644
--- a/metrics.v
+++ b/metrics.v
@@ -10,7 +10,7 @@ pub:
 }
 
 pub fn (m &Metric) str() string {
-	return '$m.name $m.labels'
+	return '${m.name} ${m.labels}'
 }
 
 pub interface MetricsCollector {
diff --git a/prometheus.v b/prometheus.v
index b4606fe..53895a8 100644
--- a/prometheus.v
+++ b/prometheus.v
@@ -27,10 +27,10 @@ fn join_two_array(arr [2]string) string {
 
 pub fn (e &PrometheusExporter) serialize_metric(metric Metric) string {
 	if metric.labels.len == 0 {
-		return '$e.prefix$metric.name'
+		return '${e.prefix}${metric.name}'
 	}
 
-	return '$e.prefix$metric.name{${metric.labels.map(join_two_array(it)).join(',')}}'
+	return '${e.prefix}${metric.name}{${metric.labels.map(join_two_array(it)).join(',')}}'
 }
 
 pub fn (mut e PrometheusExporter) export_to_string() !string {
@@ -44,14 +44,14 @@ pub fn (mut e PrometheusExporter) export_to_string() !string {
 pub fn (mut e PrometheusExporter) export_to_writer(mut writer io.Writer) ! {
 	for counter in e.collector.counters() {
 		val := e.collector.counter_get(counter) or { return error("This can't happen.") }
-		line := '${e.serialize_metric(counter)} $val\n'
+		line := '${e.serialize_metric(counter)} ${val}\n'
 
 		writer.write(line.bytes())!
 	}
 
 	for gauge in e.collector.gauges() {
 		val := e.collector.gauge_get(gauge) or { return error("This can't happen.") }
-		line := '${e.serialize_metric(gauge)} $val\n'
+		line := '${e.serialize_metric(gauge)} ${val}\n'
 
 		writer.write(line.bytes())!
 	}
@@ -63,13 +63,13 @@ pub fn (mut e PrometheusExporter) export_to_writer(mut writer io.Writer) ! {
 			...hist
 			name: '${hist.name}_count'
 		}
-		writer.write('${e.serialize_metric(m)} $hist_data.total_count\n'.bytes())!
+		writer.write('${e.serialize_metric(m)} ${hist_data.total_count}\n'.bytes())!
 
 		m = Metric{
 			...hist
 			name: '${hist.name}_sum'
 		}
-		writer.write('${e.serialize_metric(m)} $hist_data.sum\n'.bytes())!
+		writer.write('${e.serialize_metric(m)} ${hist_data.sum}\n'.bytes())!
 
 		mut le_labels := [][2]string{}
 		le_labels.prepend(hist.labels)
@@ -95,7 +95,7 @@ pub fn (mut e PrometheusExporter) export_to_writer(mut writer io.Writer) ! {
 				labels: le_labels
 			}
 
-			writer.write('${e.serialize_metric(m)} $hist_data.total_count\n'.bytes())!
+			writer.write('${e.serialize_metric(m)} ${hist_data.total_count}\n'.bytes())!
 		}
 	}
 }