diff --git a/dbrutil/composite_event_receiver.go b/dbrutil/composite_event_receiver.go
index 0f197bd..2abe03c 100644
--- a/dbrutil/composite_event_receiver.go
+++ b/dbrutil/composite_event_receiver.go
@@ -10,7 +10,8 @@ import (
 	"github.com/gocraft/dbr/v2"
 )
 
-// CompositeEventReceiver represents a composition of event receivers from dbr package and implements Composite design pattern.
+// CompositeEventReceiver represents a composition of event receivers from dbr package
+// and implements a Composite design pattern.
 type CompositeEventReceiver struct {
 	Receivers []dbr.EventReceiver
 }
diff --git a/dbrutil/metrics.go b/dbrutil/query_metrics_event_receiver.go
similarity index 78%
rename from dbrutil/metrics.go
rename to dbrutil/query_metrics_event_receiver.go
index 5527ff9..91106d0 100644
--- a/dbrutil/metrics.go
+++ b/dbrutil/query_metrics_event_receiver.go
@@ -9,10 +9,14 @@ package dbrutil
 import (
 	"time"
 
-	"github.com/acronis/go-dbkit"
 	"github.com/gocraft/dbr/v2"
 )
 
+// MetricsCollector is an interface for collecting metrics about SQL queries.
+type MetricsCollector interface {
+	ObserveQueryDuration(query string, duration time.Duration)
+}
+
 // QueryMetricsEventReceiverOpts consists options for QueryMetricsEventReceiver.
 type QueryMetricsEventReceiverOpts struct {
 	AnnotationPrefix   string
@@ -23,13 +27,15 @@ type QueryMetricsEventReceiverOpts struct {
 // To be collected, SQL query should be annotated (comment starting with specified prefix).
 type QueryMetricsEventReceiver struct {
 	*dbr.NullEventReceiver
-	metricsCollector   dbkit.MetricsCollector
+	metricsCollector   MetricsCollector
 	annotationPrefix   string
 	annotationModifier func(string) string
 }
 
 // NewQueryMetricsEventReceiverWithOpts creates a new QueryMetricsEventReceiver with additinal options.
-func NewQueryMetricsEventReceiverWithOpts(mc *dbkit.PrometheusMetrics, options QueryMetricsEventReceiverOpts) *QueryMetricsEventReceiver {
+func NewQueryMetricsEventReceiverWithOpts(
+	mc MetricsCollector, options QueryMetricsEventReceiverOpts,
+) *QueryMetricsEventReceiver {
 	return &QueryMetricsEventReceiver{
 		metricsCollector:   mc,
 		annotationPrefix:   options.AnnotationPrefix,
@@ -38,7 +44,7 @@ func NewQueryMetricsEventReceiverWithOpts(mc *dbkit.PrometheusMetrics, options Q
 }
 
 // NewQueryMetricsEventReceiver creates a new QueryMetricsEventReceiver.
-func NewQueryMetricsEventReceiver(mc *dbkit.PrometheusMetrics, annotationPrefix string) *QueryMetricsEventReceiver {
+func NewQueryMetricsEventReceiver(mc MetricsCollector, annotationPrefix string) *QueryMetricsEventReceiver {
 	options := QueryMetricsEventReceiverOpts{
 		AnnotationPrefix: annotationPrefix,
 	}
diff --git a/dbrutil/slow.go b/dbrutil/slow_query_log_event_receiver.go
similarity index 88%
rename from dbrutil/slow.go
rename to dbrutil/slow_query_log_event_receiver.go
index 9d0b8fb..2f1f934 100644
--- a/dbrutil/slow.go
+++ b/dbrutil/slow_query_log_event_receiver.go
@@ -13,7 +13,7 @@ import (
 	"github.com/gocraft/dbr/v2"
 )
 
-// SlowQueryLogEventReceiverOpts consists options for SlowQueryLogEventReceiver.
+// SlowQueryLogEventReceiverOpts contains options for SlowQueryLogEventReceiver.
 type SlowQueryLogEventReceiverOpts struct {
 	AnnotationPrefix   string
 	AnnotationModifier func(string) string
@@ -29,9 +29,10 @@ type SlowQueryLogEventReceiver struct {
 	annotationModifier func(string) string
 }
 
-// NewSlowQueryLogEventReceiverWithOpts creates a new SlowQueryLogEventReceiver with additinal options.
-func NewSlowQueryLogEventReceiverWithOpts(logger log.FieldLogger, longQueryTime time.Duration,
-	options SlowQueryLogEventReceiverOpts) *SlowQueryLogEventReceiver {
+// NewSlowQueryLogEventReceiverWithOpts creates a new SlowQueryLogEventReceiver with additional options.
+func NewSlowQueryLogEventReceiverWithOpts(
+	logger log.FieldLogger, longQueryTime time.Duration, options SlowQueryLogEventReceiverOpts,
+) *SlowQueryLogEventReceiver {
 	return &SlowQueryLogEventReceiver{
 		NullEventReceiver:  &dbr.NullEventReceiver{},
 		logger:             logger,
diff --git a/metrics.go b/metrics.go
index d066fbd..443deed 100644
--- a/metrics.go
+++ b/metrics.go
@@ -12,18 +12,14 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-type MetricsCollector interface {
-	ObserveQueryDuration(query string, duration time.Duration)
-}
-
 // PrometheusMetricsLabelQuery is a label name for SQL query in Prometheus metrics.
 const PrometheusMetricsLabelQuery = "query"
 
 // DefaultQueryDurationBuckets is default buckets into which observations of executing SQL queries are counted.
 var DefaultQueryDurationBuckets = []float64{0.001, 0.01, 0.1, 0.25, 0.5, 1, 2.5, 5, 10}
 
-// MetricsCollectorOpts represents an options for PrometheusMetrics.
-type MetricsCollectorOpts struct {
+// PrometheusMetricsOpts represents an options for PrometheusMetrics.
+type PrometheusMetricsOpts struct {
 	// Namespace is a namespace for metrics. It will be prepended to all metric names.
 	Namespace string
 
@@ -48,11 +44,11 @@ type PrometheusMetrics struct {
 
 // NewPrometheusMetrics creates a new metrics collector.
 func NewPrometheusMetrics() *PrometheusMetrics {
-	return NewPrometheusMetricsWithOpts(MetricsCollectorOpts{})
+	return NewPrometheusMetricsWithOpts(PrometheusMetricsOpts{})
 }
 
 // NewPrometheusMetricsWithOpts is a more configurable version of creating PrometheusMetrics.
-func NewPrometheusMetricsWithOpts(opts MetricsCollectorOpts) *PrometheusMetrics {
+func NewPrometheusMetricsWithOpts(opts PrometheusMetricsOpts) *PrometheusMetrics {
 	queryDurationBuckets := opts.QueryDurationBuckets
 	if queryDurationBuckets == nil {
 		queryDurationBuckets = DefaultQueryDurationBuckets