diff --git a/auth/jwt/transport_test.go b/auth/jwt/transport_test.go
index 83d0f17f8..f20055be2 100644
--- a/auth/jwt/transport_test.go
+++ b/auth/jwt/transport_test.go
@@ -76,7 +76,7 @@ func TestGRPCToContext(t *testing.T) {
 	}
 
 	// Invalid Authorization header is passed
-	md["authorization"] = []string{fmt.Sprintf("%s", signedKey)}
+	md["authorization"] = []string{signedKey}
 	ctx = reqFunc(context.Background(), md)
 	token = ctx.Value(JWTTokenContextKey)
 	if token != nil {
diff --git a/cmd/kitgen/path_test.go b/cmd/kitgen/path_test.go
index 818d89cd7..10a71cfe0 100644
--- a/cmd/kitgen/path_test.go
+++ b/cmd/kitgen/path_test.go
@@ -40,7 +40,7 @@ func TestImportPathSadpath(t *testing.T) {
 			if actual != "" {
 				t.Errorf("Expected empty path, got %q", actual)
 			}
-			if strings.Index(err.Error(), expected) == -1 {
+			if !strings.Contains(err.Error(), expected) {
 				t.Errorf("Expected %q to include %q", err, expected)
 			}
 		})
diff --git a/cmd/kitgen/transform.go b/cmd/kitgen/transform.go
index a66ff96da..112fe38b3 100644
--- a/cmd/kitgen/transform.go
+++ b/cmd/kitgen/transform.go
@@ -59,7 +59,7 @@ func importPath(targetDir, gopath string) (string, error) {
 		if err != nil {
 			continue
 		}
-		if strings.Index(res, "..") == -1 {
+		if !strings.Contains(res, "..") {
 			return res, nil
 		}
 	}
diff --git a/log/sync_test.go b/log/sync_test.go
index 253f256d1..fd7cdfd0f 100644
--- a/log/sync_test.go
+++ b/log/sync_test.go
@@ -58,8 +58,7 @@ func TestSwapLoggerConcurrency(t *testing.T) {
 }
 
 func TestSyncLoggerConcurrency(t *testing.T) {
-	var w io.Writer
-	w = &bytes.Buffer{}
+	var w io.Writer = &bytes.Buffer{}
 	logger := log.NewLogfmtLogger(w)
 	logger = log.NewSyncLogger(logger)
 	testConcurrency(t, logger, 10000)
diff --git a/metrics/generic/generic.go b/metrics/generic/generic.go
index b69334507..39216c04f 100644
--- a/metrics/generic/generic.go
+++ b/metrics/generic/generic.go
@@ -182,7 +182,7 @@ func (h *Histogram) LabelValues() []string {
 func (h *Histogram) Print(w io.Writer) {
 	h.h.RLock()
 	defer h.h.RUnlock()
-	fmt.Fprintf(w, h.h.String())
+	fmt.Fprint(w, h.h.String())
 }
 
 // safeHistogram exists as gohistogram.Histogram is not goroutine-safe.
diff --git a/sd/etcd/client_test.go b/sd/etcd/client_test.go
index 1bdb7aee9..e53565e9c 100644
--- a/sd/etcd/client_test.go
+++ b/sd/etcd/client_test.go
@@ -1,11 +1,11 @@
 package etcd
 
 import (
+	"context"
 	"errors"
 	"reflect"
 	"testing"
 	"time"
-	"context"
 
 	etcd "go.etcd.io/etcd/client"
 )
@@ -135,7 +135,7 @@ func (fw *fakeWatcher) Next(context.Context) (*etcd.Response, error) {
 			return nil, nil
 		case <-fw.err:
 			return nil, errors.New("error from underlying etcd watcher")
-		default:
+
 		}
 	}
 }
diff --git a/sd/zk/client_test.go b/sd/zk/client_test.go
index e201536d8..f335ab4d3 100644
--- a/sd/zk/client_test.go
+++ b/sd/zk/client_test.go
@@ -63,7 +63,7 @@ func TestNewClient(t *testing.T) {
 	if want, have := sessionTimeout, clientImpl.sessionTimeout; want != have {
 		t.Errorf("want %d, have %d", want, have)
 	}
-	if want, have := payload, clientImpl.rootNodePayload; bytes.Compare(want[0], have[0]) != 0 || bytes.Compare(want[1], have[1]) != 0 {
+	if want, have := payload, clientImpl.rootNodePayload; !bytes.Equal(want[0], have[0]) || !bytes.Equal(want[1], have[1]) {
 		t.Errorf("want %s, have %s", want, have)
 	}
 
diff --git a/transport/http/proto/proto_test.go b/transport/http/proto/proto_test.go
index 7b59d71a2..070bbec02 100644
--- a/transport/http/proto/proto_test.go
+++ b/transport/http/proto/proto_test.go
@@ -1,6 +1,7 @@
 package proto
 
 import (
+	"context"
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
@@ -14,7 +15,7 @@ func TestEncodeProtoRequest(t *testing.T) {
 
 	r := httptest.NewRequest(http.MethodGet, "/cat", nil)
 
-	err := EncodeProtoRequest(nil, r, cat)
+	err := EncodeProtoRequest(context.TODO(), r, cat)
 	if err != nil {
 		t.Errorf("expected no encoding errors but got: %s", err)
 		return
@@ -51,7 +52,7 @@ func TestEncodeProtoResponse(t *testing.T) {
 
 	wr := httptest.NewRecorder()
 
-	err := EncodeProtoResponse(nil, wr, cat)
+	err := EncodeProtoResponse(context.TODO(), wr, cat)
 	if err != nil {
 		t.Errorf("expected no encoding errors but got: %s", err)
 		return