diff --git a/CHANGELOG.md b/CHANGELOG.md
index 97414f1..f06499a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Changed `Queue` function to not to convert the provided queue name to lowercase. Queue names are now case-sensitive.
+
 ## [0.18.1] - 2020-07-04
 
 ### Changed
diff --git a/client.go b/client.go
index cf67461..768135c 100644
--- a/client.go
+++ b/client.go
@@ -6,7 +6,6 @@ package asynq
 
 import (
 	"fmt"
-	"strings"
 	"sync"
 	"time"
 
@@ -93,10 +92,8 @@ func (n retryOption) Type() OptionType   { return MaxRetryOpt }
 func (n retryOption) Value() interface{} { return int(n) }
 
 // Queue returns an option to specify the queue to enqueue the task into.
-//
-// Queue name is case-insensitive and the lowercased version is used.
 func Queue(qname string) Option {
-	return queueOption(strings.ToLower(qname))
+	return queueOption(qname)
 }
 
 func (qname queueOption) String() string     { return fmt.Sprintf("Queue(%q)", string(qname)) }
@@ -207,11 +204,11 @@ func composeOptions(opts ...Option) (option, error) {
 		case retryOption:
 			res.retry = int(opt)
 		case queueOption:
-			trimmed := strings.TrimSpace(string(opt))
-			if err := base.ValidateQueueName(trimmed); err != nil {
+			qname := string(opt)
+			if err := base.ValidateQueueName(qname); err != nil {
 				return option{}, err
 			}
-			res.queue = trimmed
+			res.queue = qname
 		case timeoutOption:
 			res.timeout = time.Duration(opt)
 		case deadlineOption:
diff --git a/client_test.go b/client_test.go
index bc2a4ee..5a50a2f 100644
--- a/client_test.go
+++ b/client_test.go
@@ -287,13 +287,13 @@ func TestClientEnqueue(t *testing.T) {
 			},
 		},
 		{
-			desc: "Queue option should be case-insensitive",
+			desc: "Queue option should be case sensitive",
 			task: task,
 			opts: []Option{
-				Queue("HIGH"),
+				Queue("MyQueue"),
 			},
 			wantInfo: &TaskInfo{
-				Queue:         "high",
+				Queue:         "MyQueue",
 				Type:          task.Type(),
 				Payload:       task.Payload(),
 				State:         TaskStatePending,
@@ -306,12 +306,12 @@ func TestClientEnqueue(t *testing.T) {
 				NextProcessAt: now,
 			},
 			wantPending: map[string][]*base.TaskMessage{
-				"high": {
+				"MyQueue": {
 					{
 						Type:     task.Type(),
 						Payload:  task.Payload(),
 						Retry:    defaultMaxRetry,
-						Queue:    "high",
+						Queue:    "MyQueue",
 						Timeout:  int64(defaultTimeout.Seconds()),
 						Deadline: noDeadline.Unix(),
 					},
diff --git a/internal/base/base.go b/internal/base/base.go
index 54bd3de..e2e9126 100644
--- a/internal/base/base.go
+++ b/internal/base/base.go
@@ -10,6 +10,7 @@ import (
 	"crypto/md5"
 	"encoding/hex"
 	"fmt"
+	"strings"
 	"sync"
 	"time"
 
@@ -85,7 +86,7 @@ func TaskStateFromString(s string) (TaskState, error) {
 // ValidateQueueName validates a given qname to be used as a queue name.
 // Returns nil if valid, otherwise returns non-nil error.
 func ValidateQueueName(qname string) error {
-	if len(qname) == 0 {
+	if len(strings.TrimSpace(qname)) == 0 {
 		return fmt.Errorf("queue name must contain one or more characters")
 	}
 	return nil
diff --git a/server.go b/server.go
index 41cda4b..93d3c6a 100644
--- a/server.go
+++ b/server.go
@@ -295,6 +295,9 @@ func NewServer(r RedisConnOpt, cfg Config) *Server {
 	}
 	queues := make(map[string]int)
 	for qname, p := range cfg.Queues {
+		if err := base.ValidateQueueName(qname); err != nil {
+			continue // ignore invalid queue names
+		}
 		if p > 0 {
 			queues[qname] = p
 		}