diff --git a/Gopkg.lock b/Gopkg.lock
index 3b6ea521..b67395bc 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -188,12 +188,12 @@
   revision = "197f4ad8db8d1b04ff408042119176907c971f0a"
 
 [[projects]]
-  digest = "1:1d7e1867c49a6dd9856598ef7c3123604ea3daabf5b83f303ff457bcbc410b1d"
+  digest = "1:c45802472e0c06928cd997661f2af610accd85217023b1d5f6331bebce0671d3"
   name = "github.com/pkg/errors"
   packages = ["."]
   pruneopts = ""
-  revision = "ba968bfe8b2f7e042a574c888954fccecfa385b4"
-  version = "v0.8.1"
+  revision = "614d223910a179a466c1767a985424175c39b465"
+  version = "v0.9.1"
 
 [[projects]]
   digest = "1:55dcddb2ba6ab25098ee6b96f176f39305f1fde7ea3d138e7e10bb64a5bf45be"
diff --git a/src/go/mongolib/util/util.go b/src/go/mongolib/util/util.go
index f27cd247..5936dca1 100644
--- a/src/go/mongolib/util/util.go
+++ b/src/go/mongolib/util/util.go
@@ -13,11 +13,12 @@ import (
 )
 
 const (
-	shardingNotEnabledError = 203
+	shardingNotEnabledErrorCode = 203
 )
 
 var (
-	CANNOT_GET_QUERY_ERROR = errors.New("cannot get query field from the profile document (it is not a map)")
+	CANNOT_GET_QUERY_ERROR  = errors.New("cannot get query field from the profile document (it is not a map)")
+	ShardingNotEnabledError = errors.New("sharding not enabled")
 )
 
 func GetReplicasetMembers(ctx context.Context, clientOptions *options.ClientOptions) ([]proto.Members, error) {
@@ -95,7 +96,7 @@ func GetReplicasetMembers(ctx context.Context, clientOptions *options.ClientOpti
 			membersMap[m.Name] = m
 		}
 
-		client.Disconnect(ctx)
+		client.Disconnect(ctx) //nolint
 	}
 
 	for _, member := range membersMap {
@@ -122,8 +123,8 @@ func GetHostnames(ctx context.Context, client *mongo.Client) ([]string, error) {
 	var shardsMap proto.ShardsMap
 	smRes := client.Database("admin").RunCommand(ctx, primitive.M{"getShardMap": 1})
 	if smRes.Err() != nil {
-		if e, ok := smRes.Err().(mongo.CommandError); ok && e.Code == shardingNotEnabledError {
-			return nil, nil // standalone instance
+		if e, ok := smRes.Err().(mongo.CommandError); ok && e.Code == shardingNotEnabledErrorCode {
+			return nil, ShardingNotEnabledError // standalone instance
 		}
 		return nil, errors.Wrap(smRes.Err(), "cannot getShardMap for GetHostnames")
 	}
diff --git a/src/go/mongolib/util/util_test.go b/src/go/mongolib/util/util_test.go
index ec6a2ca7..2165e243 100644
--- a/src/go/mongolib/util/util_test.go
+++ b/src/go/mongolib/util/util_test.go
@@ -162,7 +162,7 @@ func TestGetShardedHosts(t *testing.T) {
 				t.Errorf("Cannot get a new client for host %s: %s", test.uri, err)
 			}
 			if client == nil {
-				panic(fmt.Sprintf("i: %d, uri: %s\n", i, test.uri))
+				t.Fatalf("mongodb client is nil i: %d, uri: %s\n", i, test.uri)
 			}
 
 			if err := client.Connect(ctx); err != nil {
diff --git a/src/go/pt-mongodb-summary/main.go b/src/go/pt-mongodb-summary/main.go
index fe6c0d9d..b5d9a014 100644
--- a/src/go/pt-mongodb-summary/main.go
+++ b/src/go/pt-mongodb-summary/main.go
@@ -38,13 +38,19 @@ const (
 	DefaultRunningOpsSamples  = 5
 	DefaultOutputFormat       = "text"
 	typeMongos                = "mongos"
+
+	// Exit Codes
+	cannotFormatResults              = 1
+	cannotParseCommandLineParameters = 2
+	cannotGetHostInfo                = 3
+	cannotGetReplicasetMembers       = 4
 )
 
 var (
 	Build     string = "2020-04-23" // nolint
 	GoVersion string = "1.14.1"     // nolint
-	Version   string = "3.2.0"      // nolint
-	Commit    string                // nolint
+	Version   string = "3.2.0"
+	Commit    string
 )
 
 type TimedStats struct {
@@ -158,7 +164,7 @@ func main() {
 	opts, err := parseFlags()
 	if err != nil {
 		log.Errorf("cannot get parameters: %s", err.Error())
-		os.Exit(2)
+		os.Exit(cannotParseCommandLineParameters)
 	}
 	if opts == nil && err == nil {
 		return
@@ -206,7 +212,7 @@ func main() {
 	defer client.Disconnect(ctx) // nolint
 
 	hostnames, err := util.GetHostnames(ctx, client)
-	if err != nil {
+	if err != nil && errors.Is(err, util.ShardingNotEnabledError) {
 		log.Errorf("Cannot get hostnames: %s", err)
 	}
 	log.Debugf("hostnames: %v", hostnames)
@@ -217,12 +223,12 @@ func main() {
 	if err != nil {
 		message := fmt.Sprintf("Cannot get host info for %q: %s", opts.Host, err.Error())
 		log.Errorf(message)
-		os.Exit(2)
+		os.Exit(cannotGetHostInfo)
 	}
 
 	if ci.ReplicaMembers, err = util.GetReplicasetMembers(ctx, clientOptions); err != nil {
 		log.Warnf("[Error] cannot get replicaset members: %v\n", err)
-		os.Exit(2)
+		os.Exit(cannotGetReplicasetMembers)
 	}
 	log.Debugf("replicaMembers:\n%+v\n", ci.ReplicaMembers)
 
@@ -270,10 +276,9 @@ func main() {
 	out, err := formatResults(ci, opts.OutputFormat)
 	if err != nil {
 		log.Errorf("Cannot format the results: %s", err.Error())
-		os.Exit(1)
+		os.Exit(cannotFormatResults)
 	}
 	fmt.Println(string(out))
-
 }
 
 func formatResults(ci *collectedInfo, format string) ([]byte, error) {