diff --git a/pkg/address/address.go b/pkg/address/address.go
index 75f4736..f4ce016 100644
--- a/pkg/address/address.go
+++ b/pkg/address/address.go
@@ -30,12 +30,12 @@ func IPPortFromString(addr string) (*net.IPAddr, int, error) {
 	}
 	ip, err := net.ResolveIPAddr("ip", host)
 	if err != nil {
-		return nil, 0, fmt.Errorf("Unable to resolve %s: %s", host, err)
+		return nil, 0, fmt.Errorf("unable to resolve %s: %s", host, err)
 	}
 
 	port, err := strconv.Atoi(portStr)
 	if err != nil || port < 0 || port > 65535 {
-		return nil, 0, fmt.Errorf("Bad port %s: %s", portStr, err)
+		return nil, 0, fmt.Errorf("bad port %s: %s", portStr, err)
 	}
 
 	return ip, port, nil
diff --git a/pkg/registry/registry.go b/pkg/registry/registry.go
index 7ce70e0..e5d393e 100644
--- a/pkg/registry/registry.go
+++ b/pkg/registry/registry.go
@@ -157,7 +157,7 @@ func (r *Registry) GetCounter(metricName string, labels prometheus.Labels, help
 	}
 
 	if r.MetricConflicts(metricName, metrics.CounterMetricType) {
-		return nil, fmt.Errorf("Metric with name %s is already registered", metricName)
+		return nil, fmt.Errorf("metric with name %s is already registered", metricName)
 	}
 
 	var counterVec *prometheus.CounterVec