diff --git a/.codecov.yml b/.codecov.yml
index def78dc007..691bb6d2f4 100644
--- a/.codecov.yml
+++ b/.codecov.yml
@@ -1,10 +1,15 @@
 codecov:
   require_ci_to_pass: yes
 
+flags:
+  full_coverage:
+    joined: false
+
 ignore:
   - "**/*_gen.go"
   - "**/*_gen_test.go"
   - "**/generated"
+  - "**/*_string.go"  # ignore stringer-generated code
 
 coverage:
   status:
diff --git a/.github/workflows/ci-nightly.yml b/.github/workflows/ci-nightly.yml
index 049fa67d4f..577953ef5d 100644
--- a/.github/workflows/ci-nightly.yml
+++ b/.github/workflows/ci-nightly.yml
@@ -103,13 +103,15 @@ jobs:
         run: |
           ./scripts/configure_dev.sh
           PACKAGES="$(go list ./... | grep -v /go-algorand/test/)"
-          export PACKAGE_NAMES=$(echo $PACKAGES | tr -d '\n')          
+          export PACKAGE_NAMES=$(echo $PACKAGES | tr -d '\n')
+          COVERPACKAGES="$(go list ./... | grep -E -v '/go-algorand/(test|debug|cmd|config/defaultsGenerator|tools)' | grep -E -v '(test|testing|mock|mocks)$' | paste -sd ',' -)"
           mkdir -p test_results/${{ matrix.platform }}_test_nightly/${PARTITION_ID}
           go tool -modfile=tool.mod gotestsum --format standard-quiet \
             --junitfile ~/test_results/${{ matrix.platform }}_test_nightly/${PARTITION_ID}/results.xml \
             --jsonfile ~/test_results/${{ matrix.platform }}_test_nightly/${PARTITION_ID}/testresults.json \
             -- --tags "sqlite_unlock_notify sqlite_omit_load_extension" \
             -race -timeout 1h -coverprofile=coverage.txt -covermode=atomic -p 1 \
+            -coverpkg=$COVERPACKAGES \
             $PACKAGE_NAMES
       - name: Notify Slack on failure
         if: failure()
@@ -142,6 +144,7 @@ jobs:
         with:
           token: ${{ env.CODECOV_TOKEN }}
           file: ./coverage.txt
+          flags: full_coverage
           fail_ci_if_error: false
       - name: Upload test results to Codecov
         if: ${{ !cancelled() }}
diff --git a/.github/workflows/ci-pr.yml b/.github/workflows/ci-pr.yml
index 0a97bfab28..876215417a 100644
--- a/.github/workflows/ci-pr.yml
+++ b/.github/workflows/ci-pr.yml
@@ -4,6 +4,13 @@ on:
     branches:
       - master
       - 'rel/**'
+  workflow_dispatch:
+    inputs:
+      full_coverage:
+        description: 'Run with -coverpkg to measure cross-package coverage (slower)'
+        required: false
+        type: boolean
+        default: false
 
 env:
   CODECOV_TOKEN: "8b4a1f91-f154-4c26-b84c-c9aaa90159c6"  # Same public token from CircleCI config
@@ -49,13 +56,19 @@ jobs:
       - name: Run tests
         run: |
           PACKAGES="$(go list ./... | grep -v /go-algorand/test/)"
-          export PACKAGE_NAMES=$(echo $PACKAGES | tr -d '\n')          
+          export PACKAGE_NAMES=$(echo $PACKAGES | tr -d '\n')
+          COVERPKG_FLAG=""
+          if [[ "${{ inputs.full_coverage }}" == "true" ]]; then
+            COVERPACKAGES="$(go list ./... | grep -E -v '/go-algorand/(test|debug|cmd|config/defaultsGenerator|tools)' | grep -E -v '(test|testing|mock|mocks)$' | paste -sd ',' -)"
+            COVERPKG_FLAG="-coverpkg=$COVERPACKAGES"
+          fi
           mkdir -p test_results/${{ matrix.platform }}_test/${PARTITION_ID}
           go tool -modfile=tool.mod gotestsum --format standard-quiet \
             --junitfile ~/test_results/${{ matrix.platform }}_test/${PARTITION_ID}/results.xml \
             --jsonfile ~/test_results/${{ matrix.platform }}_test/${PARTITION_ID}/testresults.json \
             -- --tags "sqlite_unlock_notify sqlite_omit_load_extension" $SHORTTEST \
             -race -timeout 1h -coverprofile=coverage.txt -covermode=atomic -p 4 \
+            $COVERPKG_FLAG \
             $PACKAGE_NAMES
       - name: Notify Slack on failure
         if: failure()
@@ -89,6 +102,7 @@ jobs:
         with:
           token: ${{ env.CODECOV_TOKEN }}
           file: ./coverage.txt
+          flags: ${{ inputs.full_coverage && 'full_coverage' || '' }}
           fail_ci_if_error: false
       - name: Upload test results to Codecov
         if: ${{ !cancelled() }}
diff --git a/Makefile b/Makefile
index ee4099c1c2..e9552dcafc 100644
--- a/Makefile
+++ b/Makefile
@@ -84,6 +84,7 @@ GOLDFLAGS := $(GOLDFLAGS_BASE) \
 		 -X github.com/algorand/go-algorand/config.Channel=$(CHANNEL)
 
 UNIT_TEST_SOURCES := $(sort $(shell GOPATH=$(GOPATH) && GO111MODULE=off && go list ./... | grep -v /go-algorand/test/ ))
+COVERPKG_PACKAGES := $(sort $(shell GOPATH=$(GOPATH) && GO111MODULE=off && go list ./... | egrep -v '/go-algorand/(test|debug|cmd|config/defaultsGenerator|tools)' | egrep -v '(test|testing|mocks|mock)$$' ))
 ALGOD_API_PACKAGES := $(sort $(shell GOPATH=$(GOPATH) && GO111MODULE=off && cd daemon/algod/api; go list ./... ))
 
 GOMOD_DIRS := ./tools/block-generator ./tools/x-repo-types
@@ -132,8 +133,19 @@ check_shell:
 
 sanity: fix lint fmt tidy modernize
 
+# "make cover" runs all tests, and collects full coverage across all go-algorand packages by setting -coverpkg.
+# Without setting -coverpkg, coverage reports only measure lines of code exercised within the same package as the tests.
+#
+# "make cover PACKAGE=X" runs all tests in package github.com/algorand/go-algorand/X/... and collects full coverage
+# across all packages that are dependencies of that package.
 cover:
-	go test $(GOTAGS) -coverprofile=cover.out $(UNIT_TEST_SOURCES)
+ifeq ($(PACKAGE),)
+	$(GOTESTCOMMAND) $(GOTAGS) -coverprofile=cover.out $(UNIT_TEST_SOURCES) -covermode=atomic -coverpkg=$(shell echo $(COVERPKG_PACKAGES) | sed 's/ /,/g')
+else
+	cd $(PACKAGE); \
+	$(GOTESTCOMMAND) $(GOTAGS) -coverprofile=cover.out ./... -covermode=atomic -coverpkg=$$( (go list -f '{{ join .Deps "\n" }}' ./...; go list -f '{{ join .TestImports "\n" }}' ./...) | grep 'github.com/algorand/go-algorand' | egrep -v '/go-algorand/(test|debug|cmd|config/defaultsGenerator|tools)' | egrep -v '(test|testing|mocks|mock)$$' | sort | uniq | paste -sd ',' -); \
+	go tool cover -html cover.out
+endif
 
 prof:
 	cd node && go test $(GOTAGS) -cpuprofile=cpu.out -memprofile=mem.out -mutexprofile=mutex.out
diff --git a/ledger/metrics.go b/ledger/metrics.go
index aeae7e7853..52e3ebd0c6 100644
--- a/ledger/metrics.go
+++ b/ledger/metrics.go
@@ -31,31 +31,38 @@ type metricsTracker struct {
 	ledgerRewardClaimsTotal *metrics.Counter
 	ledgerRound             *metrics.Gauge
 	ledgerDBRound           *metrics.Gauge
+	registry                *metrics.Registry
 }
 
 func (mt *metricsTracker) loadFromDisk(l ledgerForTracker, _ basics.Round) error {
-	mt.ledgerTransactionsTotal = metrics.MakeCounter(metrics.LedgerTransactionsTotal)
-	mt.ledgerRewardClaimsTotal = metrics.MakeCounter(metrics.LedgerRewardClaimsTotal)
-	mt.ledgerRound = metrics.MakeGauge(metrics.LedgerRound)
-	mt.ledgerDBRound = metrics.MakeGauge(metrics.LedgerDBRound)
+	reg := mt.registry
+	mt.ledgerTransactionsTotal = metrics.MakeCounterUnregistered(metrics.LedgerTransactionsTotal)
+	mt.ledgerTransactionsTotal.Register(reg)
+	mt.ledgerRewardClaimsTotal = metrics.MakeCounterUnregistered(metrics.LedgerRewardClaimsTotal)
+	mt.ledgerRewardClaimsTotal.Register(reg)
+	mt.ledgerRound = metrics.MakeGaugeUnregistered(metrics.LedgerRound)
+	mt.ledgerRound.Register(reg)
+	mt.ledgerDBRound = metrics.MakeGaugeUnregistered(metrics.LedgerDBRound)
+	mt.ledgerDBRound.Register(reg)
 	return nil
 }
 
 func (mt *metricsTracker) close() {
+	reg := mt.registry
 	if mt.ledgerTransactionsTotal != nil {
-		mt.ledgerTransactionsTotal.Deregister(nil)
+		mt.ledgerTransactionsTotal.Deregister(reg)
 		mt.ledgerTransactionsTotal = nil
 	}
 	if mt.ledgerRewardClaimsTotal != nil {
-		mt.ledgerRewardClaimsTotal.Deregister(nil)
+		mt.ledgerRewardClaimsTotal.Deregister(reg)
 		mt.ledgerRewardClaimsTotal = nil
 	}
 	if mt.ledgerRound != nil {
-		mt.ledgerRound.Deregister(nil)
+		mt.ledgerRound.Deregister(reg)
 		mt.ledgerRound = nil
 	}
 	if mt.ledgerDBRound != nil {
-		mt.ledgerDBRound.Deregister(nil)
+		mt.ledgerDBRound.Deregister(reg)
 		mt.ledgerDBRound = nil
 	}
 }
diff --git a/ledger/metrics_test.go b/ledger/metrics_test.go
index 51ba010fed..943b44fcf8 100644
--- a/ledger/metrics_test.go
+++ b/ledger/metrics_test.go
@@ -34,7 +34,11 @@ import (
 func TestMetricsReload(t *testing.T) {
 	partitiontest.PartitionTest(t)
 
-	mt := metricsTracker{}
+	// Use a non-default registry so the test is not affected by metrics
+	// registered by other packages when running with -coverpkg.
+	registry := metrics.MakeRegistry()
+
+	mt := metricsTracker{registry: registry}
 	accts := ledgertesting.RandomAccounts(1, true)
 	ml := makeMockLedgerForTracker(t, true, 1, protocol.ConsensusCurrentVersion, []map[basics.Address]basics.AccountData{accts})
 
@@ -48,7 +52,7 @@ func TestMetricsReload(t *testing.T) {
 	mt.newBlock(blk, ledgercore.StateDelta{})
 
 	var buf strings.Builder
-	metrics.DefaultRegistry().WriteMetrics(&buf, "")
+	registry.WriteMetrics(&buf, "")
 	lines := strings.Split(buf.String(), "\n")
 	txCount := 0
 	rcCount := 0
diff --git a/scripts/travis/upload_coverage.sh b/scripts/travis/upload_coverage.sh
index 8ab3b56ea6..bdeee7e938 100755
--- a/scripts/travis/upload_coverage.sh
+++ b/scripts/travis/upload_coverage.sh
@@ -3,7 +3,7 @@
 set -eo pipefail
 
 if [[ -z "$CODECOV_TOKEN" ]]; then
-  /usr/bin/env bash scripts/travis/codecov
+  /usr/bin/env bash scripts/travis/codecov "$@"
 else
-  /usr/bin/env bash scripts/travis/codecov -t $CODECOV_TOKEN
+  /usr/bin/env bash scripts/travis/codecov -t $CODECOV_TOKEN "$@"
 fi
diff --git a/util/metrics/counter.go b/util/metrics/counter.go
index 54781661f9..b2bbc951b0 100644
--- a/util/metrics/counter.go
+++ b/util/metrics/counter.go
@@ -28,14 +28,14 @@ type Counter struct {
 
 // MakeCounter create a new counter with the provided name and description.
 func MakeCounter(metric MetricName) *Counter {
-	c := makeCounter(metric)
+	c := MakeCounterUnregistered(metric)
 	c.Register(nil)
 	return c
 }
 
-// makeCounter create a new counter with the provided name and description
+// MakeCounterUnregistered creates a new counter with the provided name and description
 // but does not register it with the default registry.
-func makeCounter(metric MetricName) *Counter {
+func MakeCounterUnregistered(metric MetricName) *Counter {
 	c := &Counter{c: couge{
 		values:        make([]*cougeValues, 0),
 		description:   metric.Description,
diff --git a/util/metrics/counter_test.go b/util/metrics/counter_test.go
index 51e2d44691..9e28a49bd1 100644
--- a/util/metrics/counter_test.go
+++ b/util/metrics/counter_test.go
@@ -38,6 +38,9 @@ func TestMetricCounter(t *testing.T) {
 		MetricTest: NewMetricTest(),
 	}
 
+	// create a non-default registry for the metrics in this test
+	registry := MakeRegistry()
+
 	// create a http listener.
 	port := test.createListener("127.0.0.1:0")
 
@@ -46,10 +49,12 @@ func TestMetricCounter(t *testing.T) {
 		Labels: map[string]string{
 			"host_name":  "host_one",
 			"session_id": "AFX-229"},
+		registry: registry,
 	})
 	metricService.Start(context.Background())
 
-	counter := MakeCounter(MetricName{Name: "metric_test_name1", Description: "this is the metric test for counter object"})
+	counter := MakeCounterUnregistered(MetricName{Name: "metric_test_name1", Description: "this is the metric test for counter object"})
+	counter.Register(registry)
 
 	for i := 0; i < 20; i++ {
 		counter.Inc(map[string]string{"pid": "123", "data_host": fmt.Sprintf("host%d", i%5)})
@@ -61,7 +66,7 @@ func TestMetricCounter(t *testing.T) {
 
 	metricService.Shutdown()
 
-	counter.Deregister(nil)
+	counter.Deregister(registry)
 	// test the metrics values.
 
 	test.Lock()
@@ -84,6 +89,9 @@ func TestMetricCounterFastInts(t *testing.T) {
 		MetricTest: NewMetricTest(),
 	}
 
+	// create a non-default registry for the metrics in this test
+	registry := MakeRegistry()
+
 	// create a http listener.
 	port := test.createListener("127.0.0.1:0")
 
@@ -92,10 +100,12 @@ func TestMetricCounterFastInts(t *testing.T) {
 		Labels: map[string]string{
 			"host_name":  "host_one",
 			"session_id": "AFX-229"},
+		registry: registry,
 	})
 	metricService.Start(context.Background())
 
-	counter := MakeCounter(MetricName{Name: "metric_test_name1", Description: "this is the metric test for counter object"})
+	counter := MakeCounterUnregistered(MetricName{Name: "metric_test_name1", Description: "this is the metric test for counter object"})
+	counter.Register(registry)
 
 	for i := 0; i < 20; i++ {
 		counter.Inc(nil)
@@ -108,7 +118,7 @@ func TestMetricCounterFastInts(t *testing.T) {
 
 	metricService.Shutdown()
 
-	counter.Deregister(nil)
+	counter.Deregister(registry)
 	// test the metrics values.
 
 	test.Lock()
@@ -131,6 +141,9 @@ func TestMetricCounterMixed(t *testing.T) {
 		MetricTest: NewMetricTest(),
 	}
 
+	// create a non-default registry for the metrics in this test
+	registry := MakeRegistry()
+
 	// create a http listener.
 	port := test.createListener("127.0.0.1:0")
 
@@ -139,10 +152,12 @@ func TestMetricCounterMixed(t *testing.T) {
 		Labels: map[string]string{
 			"host_name":  "host_one",
 			"session_id": "AFX-229"},
+		registry: registry,
 	})
 	metricService.Start(context.Background())
 
-	counter := MakeCounter(MetricName{Name: "metric_test_name1", Description: "this is the metric test for counter object"})
+	counter := MakeCounterUnregistered(MetricName{Name: "metric_test_name1", Description: "this is the metric test for counter object"})
+	counter.Register(registry)
 
 	counter.AddUint64(5, nil)
 	counter.AddUint64(8, map[string]string{})
@@ -157,7 +172,7 @@ func TestMetricCounterMixed(t *testing.T) {
 
 	metricService.Shutdown()
 
-	counter.Deregister(nil)
+	counter.Deregister(registry)
 	// test the metrics values.
 
 	test.Lock()
diff --git a/util/metrics/gauge.go b/util/metrics/gauge.go
index eabf156720..bf7d3b6940 100644
--- a/util/metrics/gauge.go
+++ b/util/metrics/gauge.go
@@ -27,14 +27,14 @@ type Gauge struct {
 
 // MakeGauge create a new gauge with the provided name and description.
 func MakeGauge(metric MetricName) *Gauge {
-	c := makeGauge(metric)
+	c := MakeGaugeUnregistered(metric)
 	c.Register(nil)
 	return c
 }
 
-// makeGauge create a new gauge with the provided name and description
+// MakeGaugeUnregistered creates a new gauge with the provided name and description
 // but does not register it with the default registry.
-func makeGauge(metric MetricName) *Gauge {
+func MakeGaugeUnregistered(metric MetricName) *Gauge {
 	c := &Gauge{g: couge{
 		values:        make([]*cougeValues, 0),
 		description:   metric.Description,
diff --git a/util/metrics/gauge_test.go b/util/metrics/gauge_test.go
index 679c613088..8410e1f101 100644
--- a/util/metrics/gauge_test.go
+++ b/util/metrics/gauge_test.go
@@ -37,6 +37,10 @@ func TestMetricGauge(t *testing.T) {
 	test := &GaugeTest{
 		MetricTest: NewMetricTest(),
 	}
+
+	// create a non-default registry for the metrics in this test
+	registry := MakeRegistry()
+
 	// create a http listener.
 	port := test.createListener("127.0.0.1:0")
 
@@ -45,11 +49,13 @@ func TestMetricGauge(t *testing.T) {
 		Labels: map[string]string{
 			"host_name":  "host_one",
 			"session_id": "AFX-229"},
+		registry: registry,
 	})
 	metricService.Start(context.Background())
 	gauges := make([]*Gauge, 3)
 	for i := 0; i < 3; i++ {
-		gauges[i] = MakeGauge(MetricName{Name: fmt.Sprintf("gauge_%d", i), Description: "this is the metric test for gauge object"})
+		gauges[i] = MakeGaugeUnregistered(MetricName{Name: fmt.Sprintf("gauge_%d", i), Description: "this is the metric test for gauge object"})
+		gauges[i].Register(registry)
 	}
 	for i := 0; i < 9; i++ {
 		gauges[i%3].Set(uint64(i*100 + i))
@@ -62,7 +68,7 @@ func TestMetricGauge(t *testing.T) {
 
 	metricService.Shutdown()
 	for _, gauge := range gauges {
-		gauge.Deregister(nil)
+		gauge.Deregister(registry)
 	}
 	// test the metrics values.
 
diff --git a/util/metrics/opencensus.go b/util/metrics/opencensus.go
index 4bda632887..a15136937f 100644
--- a/util/metrics/opencensus.go
+++ b/util/metrics/opencensus.go
@@ -78,7 +78,7 @@ type statCounter struct {
 // WriteMetric outputs Prometheus metrics for all labels/values in statCounter
 func (st *statCounter) WriteMetric(buf *strings.Builder, parentLabels string) {
 	name := sanitizePrometheusName(st.name)
-	counter := makeCounter(MetricName{name, st.description})
+	counter := MakeCounterUnregistered(MetricName{name, st.description})
 	for i := 0; i < len(st.labels); i++ {
 		counter.AddUint64(uint64(st.values[i]), st.labels[i])
 	}
@@ -87,7 +87,7 @@ func (st *statCounter) WriteMetric(buf *strings.Builder, parentLabels string) {
 
 // AddMetric outputs all statCounter's labels/values into a map
 func (st *statCounter) AddMetric(values map[string]float64) {
-	counter := makeCounter(MetricName{st.name, st.description})
+	counter := MakeCounterUnregistered(MetricName{st.name, st.description})
 	for i := 0; i < len(st.labels); i++ {
 		counter.AddUint64(uint64(st.values[i]), st.labels[i])
 	}
@@ -105,7 +105,7 @@ type statDistribution struct {
 // WriteMetric outputs Prometheus metrics for all labels/values in statCounter
 func (st *statDistribution) WriteMetric(buf *strings.Builder, parentLabels string) {
 	name := sanitizePrometheusName(st.name)
-	gauge := makeGauge(MetricName{name, st.description})
+	gauge := MakeGaugeUnregistered(MetricName{name, st.description})
 	for i := 0; i < len(st.labels); i++ {
 		gauge.SetLabels(uint64(st.values[i]), st.labels[i])
 	}
@@ -114,7 +114,7 @@ func (st *statDistribution) WriteMetric(buf *strings.Builder, parentLabels strin
 
 // AddMetric outputs all statCounter's labels/values into a map
 func (st *statDistribution) AddMetric(values map[string]float64) {
-	gauge := makeGauge(MetricName{st.name, st.description})
+	gauge := MakeGaugeUnregistered(MetricName{st.name, st.description})
 	for i := 0; i < len(st.labels); i++ {
 		gauge.SetLabels(uint64(st.values[i]), st.labels[i])
 	}
diff --git a/util/metrics/prometheus.go b/util/metrics/prometheus.go
index e916491fc4..d6fa5bae33 100644
--- a/util/metrics/prometheus.go
+++ b/util/metrics/prometheus.go
@@ -75,7 +75,7 @@ func collectPrometheusMetrics(names []string) []Metric {
 		}
 		if _, ok := namesMap[metric.GetName()]; len(namesMap) > 0 && ok || len(namesMap) == 0 {
 			if metric.GetType() == iopc.MetricType_COUNTER && metric.GetMetric() != nil {
-				counter := makeCounter(MetricName{metric.GetName(), metric.GetHelp()})
+				counter := MakeCounterUnregistered(MetricName{metric.GetName(), metric.GetHelp()})
 				ma := metric.GetMetric()
 				for _, m := range ma {
 					if m.GetCounter() == nil {
@@ -87,7 +87,7 @@ func collectPrometheusMetrics(names []string) []Metric {
 				}
 				result = append(result, counter)
 			} else if metric.GetType() == iopc.MetricType_GAUGE && metric.GetMetric() != nil {
-				gauge := makeGauge(MetricName{metric.GetName(), metric.GetHelp()})
+				gauge := MakeGaugeUnregistered(MetricName{metric.GetName(), metric.GetHelp()})
 
 				ma := metric.GetMetric()
 				for _, m := range ma {
diff --git a/util/metrics/registry_test.go b/util/metrics/registry_test.go
index c8251008f6..b8f91a67ed 100644
--- a/util/metrics/registry_test.go
+++ b/util/metrics/registry_test.go
@@ -27,15 +27,22 @@ import (
 func TestWriteAdd(t *testing.T) {
 	partitiontest.PartitionTest(t)
 
+	// create a non-default registry for the metrics in this test
+	registry := MakeRegistry()
+
 	// Test AddMetrics and WriteMetrics with a counter
-	counter := MakeCounter(MetricName{Name: "gauge-name", Description: "gauge description"})
+	counter := MakeCounterUnregistered(MetricName{Name: "gauge-name", Description: "gauge description"})
+	counter.Register(registry)
+
 	counter.AddUint64(12, nil)
 
-	labelCounter := MakeCounter(MetricName{Name: "label-counter", Description: "counter with labels"})
+	labelCounter := MakeCounterUnregistered(MetricName{Name: "label-counter", Description: "counter with labels"})
+	labelCounter.Register(registry)
+
 	labelCounter.AddUint64(5, map[string]string{"label": "a label value"})
 
 	results := make(map[string]float64)
-	DefaultRegistry().AddMetrics(results)
+	registry.AddMetrics(results)
 
 	require.Equal(t, 2, len(results), "results", results)
 	require.Contains(t, results, "gauge-name")
@@ -44,19 +51,19 @@ func TestWriteAdd(t *testing.T) {
 	require.InDelta(t, 5, results["label-counter_label__a_label_value_"], 0.01)
 
 	bufBefore := strings.Builder{}
-	DefaultRegistry().WriteMetrics(&bufBefore, "label")
+	registry.WriteMetrics(&bufBefore, "label")
 	require.True(t, bufBefore.Len() > 0)
 
-	DefaultRegistry().AddMetrics(results)
+	registry.AddMetrics(results)
 
 	require.Contains(t, results, "gauge-name")
 	require.InDelta(t, 12, results["gauge-name"], 0.01)
 
 	// not included in string builder
 	bufAfter := strings.Builder{}
-	DefaultRegistry().WriteMetrics(&bufAfter, "label")
+	registry.WriteMetrics(&bufAfter, "label")
 	require.Equal(t, bufBefore.String(), bufAfter.String())
 
-	counter.Deregister(nil)
-	labelCounter.Deregister(nil)
+	counter.Deregister(registry)
+	labelCounter.Deregister(registry)
 }
diff --git a/util/metrics/reporter.go b/util/metrics/reporter.go
index 07401414c6..65423691e0 100644
--- a/util/metrics/reporter.go
+++ b/util/metrics/reporter.go
@@ -121,7 +121,11 @@ func (reporter *MetricReporter) waitForTimeStamp(ctx context.Context) bool {
 
 func (reporter *MetricReporter) gatherMetrics() {
 	var buf strings.Builder
-	DefaultRegistry().WriteMetrics(&buf, reporter.formattedLabels)
+	if reporter.serviceConfig.registry != nil {
+		reporter.serviceConfig.registry.WriteMetrics(&buf, reporter.formattedLabels)
+	} else {
+		DefaultRegistry().WriteMetrics(&buf, reporter.formattedLabels)
+	}
 	reporter.lastMetricsBuffer = buf
 }
 
diff --git a/util/metrics/serviceCommon.go b/util/metrics/serviceCommon.go
index 48cf1a146c..fb7e800599 100644
--- a/util/metrics/serviceCommon.go
+++ b/util/metrics/serviceCommon.go
@@ -30,6 +30,7 @@ type ServiceConfig struct {
 	NodeExporterListenAddress string
 	Labels                    map[string]string
 	NodeExporterPath          string
+	registry                  *Registry // if nil, will use DefaultRegistry(). Used for testing
 }
 
 // MetricService represent a single running metric server instance