diff --git a/client.go b/client.go
index dc1841c..81ec5a5 100644
--- a/client.go
+++ b/client.go
@@ -5,7 +5,6 @@
 package asynq
 
 import (
-	"errors"
 	"fmt"
 	"strings"
 	"sync"
@@ -14,6 +13,7 @@ import (
 	"github.com/go-redis/redis/v7"
 	"github.com/google/uuid"
 	"github.com/hibiken/asynq/internal/base"
+	"github.com/hibiken/asynq/internal/errors"
 	"github.com/hibiken/asynq/internal/rdb"
 )
 
@@ -346,7 +346,7 @@ func (c *Client) Enqueue(task *Task, opts ...Option) (*Result, error) {
 		err = c.schedule(msg, opt.processAt, opt.uniqueTTL)
 	}
 	switch {
-	case err == rdb.ErrDuplicateTask:
+	case errors.Is(err, errors.ErrDuplicateTask):
 		return nil, fmt.Errorf("%w", ErrDuplicateTask)
 	case err != nil:
 		return nil, err
diff --git a/inspeq/inspector.go b/inspeq/inspector.go
index e300b09..2aa2e7b 100644
--- a/inspeq/inspector.go
+++ b/inspeq/inspector.go
@@ -5,7 +5,6 @@
 package inspeq
 
 import (
-	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -15,6 +14,7 @@ import (
 	"github.com/google/uuid"
 	"github.com/hibiken/asynq"
 	"github.com/hibiken/asynq/internal/base"
+	"github.com/hibiken/asynq/internal/errors"
 	"github.com/hibiken/asynq/internal/rdb"
 )
 
@@ -154,10 +154,10 @@ var (
 // returns ErrQueueNotEmpty.
 func (i *Inspector) DeleteQueue(qname string, force bool) error {
 	err := i.rdb.RemoveQueue(qname, force)
-	if _, ok := err.(*rdb.QueueNotFoundError); ok {
+	if errors.IsQueueNotFound(err) {
 		return fmt.Errorf("%w: queue=%q", ErrQueueNotFound, qname)
 	}
-	if _, ok := err.(*rdb.QueueNotEmptyError); ok {
+	if errors.IsQueueNotEmpty(err) {
 		return fmt.Errorf("%w: queue=%q", ErrQueueNotEmpty, qname)
 	}
 	return err
@@ -549,13 +549,13 @@ func (i *Inspector) DeleteTaskByKey(qname, key string) error {
 	}
 	switch prefix {
 	case keyPrefixPending:
-		return i.rdb.DeletePendingTask(qname, id)
+		return i.rdb.DeleteTask(qname, id)
 	case keyPrefixScheduled:
-		return i.rdb.DeleteScheduledTask(qname, id)
+		return i.rdb.DeleteTask(qname, id)
 	case keyPrefixRetry:
-		return i.rdb.DeleteRetryTask(qname, id)
+		return i.rdb.DeleteTask(qname, id)
 	case keyPrefixArchived:
-		return i.rdb.DeleteArchivedTask(qname, id)
+		return i.rdb.DeleteTask(qname, id)
 	default:
 		return fmt.Errorf("invalid key")
 	}
@@ -657,11 +657,11 @@ func (i *Inspector) ArchiveTaskByKey(qname, key string) error {
 	}
 	switch prefix {
 	case keyPrefixPending:
-		return i.rdb.ArchivePendingTask(qname, id)
+		return i.rdb.ArchiveTask(qname, id)
 	case keyPrefixScheduled:
-		return i.rdb.ArchiveScheduledTask(qname, id)
+		return i.rdb.ArchiveTask(qname, id)
 	case keyPrefixRetry:
-		return i.rdb.ArchiveRetryTask(qname, id)
+		return i.rdb.ArchiveTask(qname, id)
 	case keyPrefixArchived:
 		return fmt.Errorf("task is already archived")
 	default:
diff --git a/inspeq/inspector_test.go b/inspeq/inspector_test.go
index 0fedc9f..e66d70a 100644
--- a/inspeq/inspector_test.go
+++ b/inspeq/inspector_test.go
@@ -5,6 +5,7 @@
 package inspeq
 
 import (
+	"errors"
 	"flag"
 	"fmt"
 	"math"
@@ -271,7 +272,7 @@ func TestInspectorDeleteQueueErrorQueueNotEmpty(t *testing.T) {
 		h.SeedAllArchivedQueues(t, r, tc.archived)
 
 		err := inspector.DeleteQueue(tc.qname, tc.force)
-		if _, ok := err.(*ErrQueueNotEmpty); !ok {
+		if !errors.Is(err, ErrQueueNotEmpty) {
 			t.Errorf("DeleteQueue(%v, %t) did not return ErrQueueNotEmpty",
 				tc.qname, tc.force)
 		}
@@ -327,7 +328,7 @@ func TestInspectorDeleteQueueErrorQueueNotFound(t *testing.T) {
 		h.SeedAllArchivedQueues(t, r, tc.archived)
 
 		err := inspector.DeleteQueue(tc.qname, tc.force)
-		if _, ok := err.(*ErrQueueNotFound); !ok {
+		if !errors.Is(err, ErrQueueNotFound) {
 			t.Errorf("DeleteQueue(%v, %t) did not return ErrQueueNotFound",
 				tc.qname, tc.force)
 		}
diff --git a/processor.go b/processor.go
index 605d077..c1857bf 100644
--- a/processor.go
+++ b/processor.go
@@ -6,7 +6,6 @@ package asynq
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"math/rand"
 	"runtime"
@@ -17,8 +16,8 @@ import (
 	"time"
 
 	"github.com/hibiken/asynq/internal/base"
+	"github.com/hibiken/asynq/internal/errors"
 	"github.com/hibiken/asynq/internal/log"
-	"github.com/hibiken/asynq/internal/rdb"
 	"golang.org/x/time/rate"
 )
 
@@ -163,7 +162,7 @@ func (p *processor) exec() {
 		qnames := p.queues()
 		msg, deadline, err := p.broker.Dequeue(qnames...)
 		switch {
-		case err == rdb.ErrNoProcessableTask:
+		case errors.Is(err, errors.ErrNoProcessableTask):
 			p.logger.Debug("All queues are empty")
 			// Queues are empty, this is a normal behavior.
 			// Sleep to avoid slamming redis and let scheduler move tasks into queues.