diff --git a/collector/cpu_dragonfly.go b/collector/cpu_dragonfly.go
index beef390f..4ccb729d 100644
--- a/collector/cpu_dragonfly.go
+++ b/collector/cpu_dragonfly.go
@@ -17,7 +17,7 @@ package collector
 
 import (
 	"errors"
-	"fmt"
+	"strconv"
 	"unsafe"
 
 	"github.com/go-kit/kit/log"
@@ -131,7 +131,7 @@ func (c *statCollector) Update(ch chan<- prometheus.Metric) error {
 	// Export order: user nice sys intr idle
 	cpuFields := []string{"user", "nice", "sys", "interrupt", "idle"}
 	for i, value := range cpuTimes {
-		cpux := fmt.Sprintf("%d", i/fieldsCount)
+		cpux := strconv.Itoa(i / fieldsCount)
 		ch <- prometheus.MustNewConstMetric(c.cpu, prometheus.CounterValue, value, cpux, cpuFields[i%fieldsCount])
 	}
 
diff --git a/collector/cpu_linux.go b/collector/cpu_linux.go
index 1cb6f2c1..f5e9ce89 100644
--- a/collector/cpu_linux.go
+++ b/collector/cpu_linux.go
@@ -106,7 +106,7 @@ func (c *cpuCollector) updateInfo(ch chan<- prometheus.Metric) error {
 			1,
 			cpu.PhysicalID,
 			cpu.CoreID,
-			fmt.Sprintf("%d", cpu.Processor),
+			strconv.Itoa(int(cpu.Processor)),
 			cpu.VendorID,
 			cpu.CPUFamily,
 			cpu.Model,
@@ -202,7 +202,7 @@ func (c *cpuCollector) updateStat(ch chan<- prometheus.Metric) error {
 	}
 
 	for cpuID, cpuStat := range stats.CPU {
-		cpuNum := fmt.Sprintf("%d", cpuID)
+		cpuNum := strconv.Itoa(cpuID)
 		ch <- prometheus.MustNewConstMetric(c.cpu, prometheus.CounterValue, cpuStat.User, cpuNum, "user")
 		ch <- prometheus.MustNewConstMetric(c.cpu, prometheus.CounterValue, cpuStat.Nice, cpuNum, "nice")
 		ch <- prometheus.MustNewConstMetric(c.cpu, prometheus.CounterValue, cpuStat.System, cpuNum, "system")
diff --git a/collector/interrupts_openbsd.go b/collector/interrupts_openbsd.go
index 5a61e68c..c9aae3ca 100644
--- a/collector/interrupts_openbsd.go
+++ b/collector/interrupts_openbsd.go
@@ -108,7 +108,7 @@ func (c *interruptsCollector) Update(ch chan<- prometheus.Metric) error {
 			ch <- c.desc.mustNewConstMetric(
 				value,
 				strconv.Itoa(cpuNo),
-				fmt.Sprintf("%d", interrupt.vector),
+				strconv.Itoa(interrupt.vector),
 				dev,
 			)
 		}
diff --git a/collector/perf_linux.go b/collector/perf_linux.go
index 0e8a3cca..e8a52b43 100644
--- a/collector/perf_linux.go
+++ b/collector/perf_linux.go
@@ -14,8 +14,8 @@
 package collector
 
 import (
-	"fmt"
 	"runtime"
+	"strconv"
 
 	"github.com/go-kit/kit/log"
 	"github.com/hodgesds/perf-utils"
@@ -334,7 +334,7 @@ func (c *perfCollector) Update(ch chan<- prometheus.Metric) error {
 
 func (c *perfCollector) updateHardwareStats(ch chan<- prometheus.Metric) error {
 	for cpu, profiler := range c.perfHwProfilers {
-		cpuStr := fmt.Sprintf("%d", cpu)
+		cpuStr := strconv.Itoa(cpu)
 		hwProfile, err := profiler.Profile()
 		if err != nil {
 			return err
@@ -405,7 +405,7 @@ func (c *perfCollector) updateHardwareStats(ch chan<- prometheus.Metric) error {
 
 func (c *perfCollector) updateSoftwareStats(ch chan<- prometheus.Metric) error {
 	for cpu, profiler := range c.perfSwProfilers {
-		cpuStr := fmt.Sprintf("%d", cpu)
+		cpuStr := strconv.Itoa(cpu)
 		swProfile, err := profiler.Profile()
 		if err != nil {
 			return err
@@ -460,7 +460,7 @@ func (c *perfCollector) updateSoftwareStats(ch chan<- prometheus.Metric) error {
 
 func (c *perfCollector) updateCacheStats(ch chan<- prometheus.Metric) error {
 	for cpu, profiler := range c.perfCacheProfilers {
-		cpuStr := fmt.Sprintf("%d", cpu)
+		cpuStr := strconv.Itoa(cpu)
 		cacheProfile, err := profiler.Profile()
 		if err != nil {
 			return err