diff --git a/src/Commands/QueueClear.php b/src/Commands/QueueClear.php
index c57ba24..98e476e 100644
--- a/src/Commands/QueueClear.php
+++ b/src/Commands/QueueClear.php
@@ -68,7 +68,13 @@ public function run(array $params)
             return EXIT_ERROR;
         }
 
-        service('queue')->clear($queue);
+        $result = service('queue')->clear($queue);
+
+        if (! $result) {
+            CLI::error('Failed to clear the queue: ' . $queue . '.');
+
+            return EXIT_ERROR;
+        }
 
         CLI::print('Queue ', 'yellow');
         CLI::print($queue, 'light_yellow');
diff --git a/src/Handlers/PredisHandler.php b/src/Handlers/PredisHandler.php
index 62ee23e..aeaa23f 100644
--- a/src/Handlers/PredisHandler.php
+++ b/src/Handlers/PredisHandler.php
@@ -25,6 +25,7 @@
 use CodeIgniter\Queue\QueuePushResult;
 use Exception;
 use Predis\Client;
+use Predis\Command\Processor\KeyPrefixProcessor;
 use RuntimeException;
 use Throwable;
 
@@ -206,22 +207,61 @@ public function done(QueueJob $queueJob): bool
      */
     public function clear(?string $queue = null): bool
     {
-        if ($queue !== null) {
-            $keys   = $this->predis->keys("queues:{$queue}:*");
-            $result = $keys !== [] ? $this->predis->del($keys) > 0 : true;
-        } else {
-            $keys   = $this->predis->keys('queues:*');
-            $result = $keys !== [] ? $this->predis->del($keys) > 0 : true;
+        try {
+            if ($queue !== null) {
+                // Reject glob metacharacters before building the key pattern.
+                $this->validateQueue($queue);
+            }
+
+            $pattern = $queue === null ? 'queues:*' : "queues:{$queue}:*";
+            $keys    = $this->predis->keys($pattern);
+
+            if ($keys !== []) {
+                // KEYS returns full key names, including the client prefix.
+                // DEL would apply the prefix again, so strip it first.
+                $prefix = $this->getKeyPrefix();
+
+                if ($prefix !== '') {
+                    $keys = array_map(
+                        static fn (string $key): string => str_starts_with($key, $prefix) ? substr($key, strlen($prefix)) : $key,
+                        $keys,
+                    );
+                }
+
+                $this->predis->del($keys);
+            }
+        } catch (Throwable $e) {
+            log_message('error', 'Predis clear error: ' . $e->getMessage());
+
+            return false;
         }
 
-        if ($result) {
-            // Emit queue cleared event
-            QueueEventManager::queueCleared(
-                handler: $this->name(),
-                queue: $queue,
-            );
+        // Emit queue cleared event
+        QueueEventManager::queueCleared(
+            handler: $this->name(),
+            queue: $queue,
+        );
+
+        return true;
+    }
+
+    /**
+     * Get the key prefix configured for the Predis client.
+     */
+    private function getKeyPrefix(): string
+    {
+        $options = $this->predis->getOptions();
+
+        if (! $options->defined('prefix')) {
+            return '';
+        }
+
+        $prefix = $options->prefix;
+
+        if ($prefix instanceof KeyPrefixProcessor) {
+            return (string) $prefix->getPrefix();
         }
 
-        return $result;
+        return '';
     }
 }
diff --git a/src/Handlers/RedisHandler.php b/src/Handlers/RedisHandler.php
index 767de31..aa7d56c 100644
--- a/src/Handlers/RedisHandler.php
+++ b/src/Handlers/RedisHandler.php
@@ -247,22 +247,61 @@ public function done(QueueJob $queueJob): bool
      */
     public function clear(?string $queue = null): bool
     {
-        if ($queue !== null) {
-            $result = ($keys = $this->redis->keys("queues:{$queue}:*")) ? (int) $this->redis->del($keys) > 0 : true;
-        } elseif ($keys = $this->redis->keys('queues:*')) {
-            $result = (int) $this->redis->del($keys) > 0;
-        } else {
-            $result = true;
-        }
+        try {
+            if ($queue !== null) {
+                // Reject glob metacharacters before building the key pattern.
+                $this->validateQueue($queue);
+            }
 
-        if ($result) {
-            // Emit queue cleared event
-            QueueEventManager::queueCleared(
-                handler: $this->name(),
-                queue: $queue,
-            );
+            $pattern = $queue === null ? 'queues:*' : "queues:{$queue}:*";
+            $keys    = $this->redis->keys($pattern);
+
+            if ($keys === false) {
+                log_message('error', 'Redis clear error: unable to list keys for pattern ' . $pattern . '.');
+
+                return false;
+            }
+
+            if ($keys !== []) {
+                // KEYS returns full key names, including the client prefix.
+                // DEL would apply the prefix again, so strip it first.
+                $prefix = $this->normalizePrefix($this->redis->getOption(Redis::OPT_PREFIX));
+
+                if ($prefix !== '') {
+                    $prefixLength = strlen($prefix);
+
+                    $keys = array_map(
+                        static fn (string $key): string => str_starts_with($key, $prefix) ? substr($key, $prefixLength) : $key,
+                        $keys,
+                    );
+                }
+
+                if ($this->redis->del($keys) === false) {
+                    log_message('error', 'Redis clear error: unable to delete keys for pattern ' . $pattern . '.');
+
+                    return false;
+                }
+            }
+        } catch (Throwable $e) {
+            log_message('error', 'Redis clear error: ' . $e->getMessage());
+
+            return false;
         }
 
-        return $result;
+        // Emit queue cleared event
+        QueueEventManager::queueCleared(
+            handler: $this->name(),
+            queue: $queue,
+        );
+
+        return true;
+    }
+
+    /**
+     * Normalize the value returned by Redis::getOption() to a string prefix.
+     */
+    private function normalizePrefix(mixed $prefix): string
+    {
+        return is_string($prefix) ? $prefix : '';
     }
 }
diff --git a/tests/Commands/QueueClearTest.php b/tests/Commands/QueueClearTest.php
index 6024837..5fc54ca 100644
--- a/tests/Commands/QueueClearTest.php
+++ b/tests/Commands/QueueClearTest.php
@@ -13,7 +13,9 @@
 
 namespace Tests\Commands;
 
+use CodeIgniter\Queue\Interfaces\QueueInterface;
 use CodeIgniter\Test\Filters\CITestStreamFilter;
+use Config\Services;
 use Tests\Support\CLITestCase;
 
 /**
@@ -46,4 +48,25 @@ public function testRun(): void
 
         $this->assertSame('Queue test has been cleared.', $output);
     }
+
+    public function testRunFailedWhenClearReturnsFalse(): void
+    {
+        $queueMock = $this->createMock(QueueInterface::class);
+        $queueMock->expects($this->once())
+            ->method('clear')
+            ->with('test')
+            ->willReturn(false);
+
+        Services::injectMock('queue', $queueMock);
+
+        CITestStreamFilter::registration();
+        CITestStreamFilter::addErrorFilter();
+
+        $this->assertNotFalse(command('queue:clear test'));
+        $output = $this->parseOutput(CITestStreamFilter::$buffer);
+
+        CITestStreamFilter::removeErrorFilter();
+
+        $this->assertSame('Failed to clear the queue: test.', $output);
+    }
 }
diff --git a/tests/PredisHandlerTest.php b/tests/PredisHandlerTest.php
index 8fcf4e2..2ac6b34 100644
--- a/tests/PredisHandlerTest.php
+++ b/tests/PredisHandlerTest.php
@@ -375,6 +375,37 @@ public function testClearAll(): void
         $this->assertTrue($result);
     }
 
+    public function testClearWithPrefix(): void
+    {
+        $config                   = clone $this->config;
+        $config->predis['prefix'] = 'app:';
+
+        $handler = new PredisHandler($config);
+        $handler->push('queue1', 'success', ['key' => 'value']);
+
+        $predis = self::getPrivateProperty($handler, 'predis');
+        $this->assertGreaterThan(0, $predis->zcard('queues:queue1:default'));
+
+        $result = $handler->clear('queue1');
+        $this->assertTrue($result);
+        $this->assertSame(0, $predis->zcard('queues:queue1:default'));
+
+        // Clear all queues with prefix
+        $handler->push('queue1', 'success', ['key' => 'value']);
+        $this->assertTrue($handler->clear());
+        $this->assertCount(0, $predis->keys('queues:*'));
+    }
+
+    public function testClearWithInvalidQueueNameReturnsFalse(): void
+    {
+        $handler = new PredisHandler($this->config);
+
+        $this->assertFalse($handler->clear('queue*'));
+        $this->assertFalse($handler->clear('queue?'));
+        $this->assertFalse($handler->clear('queue!invalid'));
+        $this->assertFalse($handler->clear(str_repeat('a', 65)));
+    }
+
     /**
      * @throws ReflectionException
      */
diff --git a/tests/RedisHandlerTest.php b/tests/RedisHandlerTest.php
index 0b64d0b..fbe9e02 100644
--- a/tests/RedisHandlerTest.php
+++ b/tests/RedisHandlerTest.php
@@ -348,6 +348,37 @@ public function testClearAll(): void
         $this->assertTrue($result);
     }
 
+    public function testClearWithPrefix(): void
+    {
+        $config                  = clone $this->config;
+        $config->redis['prefix'] = 'app:';
+
+        $handler = new RedisHandler($config);
+        $handler->push('queue1', 'success', ['key' => 'value']);
+
+        $redis = self::getPrivateProperty($handler, 'redis');
+        $this->assertGreaterThan(0, $redis->zCard('queues:queue1:default'));
+
+        $result = $handler->clear('queue1');
+        $this->assertTrue($result);
+        $this->assertSame(0, $redis->zCard('queues:queue1:default'));
+
+        // Clear all queues with prefix
+        $handler->push('queue1', 'success', ['key' => 'value']);
+        $this->assertTrue($handler->clear());
+        $this->assertCount(0, $redis->keys('queues:*'));
+    }
+
+    public function testClearWithInvalidQueueNameReturnsFalse(): void
+    {
+        $handler = new RedisHandler($this->config);
+
+        $this->assertFalse($handler->clear('queue*'));
+        $this->assertFalse($handler->clear('queue?'));
+        $this->assertFalse($handler->clear('queue!invalid'));
+        $this->assertFalse($handler->clear(str_repeat('a', 65)));
+    }
+
     public function testRetry(): void
     {
         $handler = new RedisHandler($this->config);