diff --git a/system/Cache/Handlers/PredisHandler.php b/system/Cache/Handlers/PredisHandler.php
index 79e7ae98f916..2eae6dda20a6 100644
--- a/system/Cache/Handlers/PredisHandler.php
+++ b/system/Cache/Handlers/PredisHandler.php
@@ -20,12 +20,26 @@
 use Predis\Client;
 use Predis\Collection\Iterator\Keyspace;
 use Predis\Response\Status;
+use Throwable;
 
 /**
  * Predis cache handler
  */
 class PredisHandler extends BaseHandler
 {
+    /**
+     * Lua script to conditionally execute HMSET and EXPIREAT in a single round trip.
+     * Prevents EXPIREAT from mutating TTL or expiring keys when HMSET fails (e.g. WRONGTYPE).
+     */
+    private const SAVE_SCRIPT = <<<'LUA'
+        local res = redis.pcall('HMSET', KEYS[1], '__ci_type', ARGV[2], '__ci_value', ARGV[3])
+        if type(res) == 'table' and res.err then
+            return 0
+        end
+        redis.call('EXPIREAT', KEYS[1], ARGV[1])
+        return 1
+        LUA;
+
     /**
      * Default config
      *
@@ -118,15 +132,33 @@ public function save(string $key, mixed $value, int $ttl = 60): bool
                 return false;
         }
 
-        if (! $this->redis->hmset($key, ['__ci_type' => $dataType, '__ci_value' => $value]) instanceof Status) {
-            return false;
-        }
+        $fields = ['__ci_type' => $dataType, '__ci_value' => $value];
 
         if ($ttl !== 0) {
-            $this->redis->expireat($key, Time::now()->getTimestamp() + $ttl);
+            $expiresAt = Time::now()->getTimestamp() + $ttl;
+
+            try {
+                return (bool) $this->redis->eval(
+                    self::SAVE_SCRIPT,
+                    1,
+                    $key,
+                    (string) $expiresAt,
+                    $dataType,
+                    (string) $value,
+                );
+            } catch (Throwable) {
+                // If EVAL is unsupported or blocked, fallback to sequential execution.
+                if (! $this->redis->hmset($key, $fields) instanceof Status) {
+                    return false;
+                }
+
+                $this->redis->expireat($key, $expiresAt);
+
+                return true;
+            }
         }
 
-        return true;
+        return $this->redis->hmset($key, $fields) instanceof Status;
     }
 
     public function delete(string $key): bool
diff --git a/system/Cache/Handlers/RedisHandler.php b/system/Cache/Handlers/RedisHandler.php
index ccbb29bcd032..e008a35c59c4 100644
--- a/system/Cache/Handlers/RedisHandler.php
+++ b/system/Cache/Handlers/RedisHandler.php
@@ -18,12 +18,26 @@
 use Config\Cache;
 use Redis;
 use RedisException;
+use Throwable;
 
 /**
  * Redis cache handler
  */
 class RedisHandler extends BaseHandler
 {
+    /**
+     * Lua script to conditionally execute HMSET and EXPIREAT in a single round trip.
+     * Prevents EXPIREAT from mutating TTL or expiring keys when HMSET fails (e.g. WRONGTYPE).
+     */
+    private const SAVE_SCRIPT = <<<'LUA'
+        local res = redis.pcall('HMSET', KEYS[1], '__ci_type', ARGV[2], '__ci_value', ARGV[3])
+        if type(res) == 'table' and res.err then
+            return 0
+        end
+        redis.call('EXPIREAT', KEYS[1], ARGV[1])
+        return 1
+        LUA;
+
     /**
      * Default config
      *
@@ -134,15 +148,28 @@ public function save(string $key, mixed $value, int $ttl = 60): bool
                 return false;
         }
 
-        if (! $this->redis->hMset($key, ['__ci_type' => $dataType, '__ci_value' => $value])) {
-            return false;
-        }
+        $fields = ['__ci_type' => $dataType, '__ci_value' => $value];
 
         if ($ttl !== 0) {
-            $this->redis->expireAt($key, Time::now()->getTimestamp() + $ttl);
+            $expiresAt = Time::now()->getTimestamp() + $ttl;
+
+            try {
+                return (bool) $this->redis->eval(
+                    self::SAVE_SCRIPT,
+                    [$key, $expiresAt, $dataType, (string) $value],
+                    1,
+                );
+            } catch (Throwable) {
+                // If EVAL is unsupported or blocked, fallback to sequential execution.
+                if (! $this->redis->hMset($key, $fields)) {
+                    return false;
+                }
+
+                return $this->redis->expireAt($key, $expiresAt);
+            }
         }
 
-        return true;
+        return (bool) $this->redis->hMset($key, $fields);
     }
 
     public function delete(string $key): bool
diff --git a/tests/system/Cache/Handlers/PredisHandlerTest.php b/tests/system/Cache/Handlers/PredisHandlerTest.php
index 91949f53238f..dbe70d112bd7 100644
--- a/tests/system/Cache/Handlers/PredisHandlerTest.php
+++ b/tests/system/Cache/Handlers/PredisHandlerTest.php
@@ -18,6 +18,7 @@
 use CodeIgniter\I18n\Time;
 use Config\Cache;
 use PHPUnit\Framework\Attributes\Group;
+use Predis\Client;
 
 /**
  * @internal
@@ -196,4 +197,25 @@ public function testReconnect(): void
 
         $this->assertSame('value', $this->handler->get(self::$key1));
     }
+
+    public function testSaveFailsOnNonHashKeyPreservingValueAndTtl(): void
+    {
+        /** @var Client $redis */
+        $redis = $this->getPrivateProperty($this->handler, 'redis');
+
+        $prefixedKey = $this->config->prefix . 'non_hash_key';
+        $redis->set($prefixedKey, 'raw_string_value');
+        $redis->expire($prefixedKey, 300);
+
+        $this->assertFalse($this->handler->save('non_hash_key', 'new_value', 60));
+
+        $this->assertSame('raw_string_value', $redis->get($prefixedKey));
+        $this->assertGreaterThan(250, $redis->ttl($prefixedKey));
+
+        // Handler remains usable for subsequent operations
+        $this->assertTrue($this->handler->save(self::$key1, 'usable_value'));
+        $this->assertSame('usable_value', $this->handler->get(self::$key1));
+
+        $redis->del([$prefixedKey]);
+    }
 }
diff --git a/tests/system/Cache/Handlers/RedisHandlerTest.php b/tests/system/Cache/Handlers/RedisHandlerTest.php
index 1f85ecc28349..4dbd06452169 100644
--- a/tests/system/Cache/Handlers/RedisHandlerTest.php
+++ b/tests/system/Cache/Handlers/RedisHandlerTest.php
@@ -19,6 +19,7 @@
 use Config\Cache;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\Group;
+use Redis;
 
 /**
  * @internal
@@ -238,4 +239,25 @@ public function testReconnect(): void
 
         $this->assertSame('value', $this->handler->get(self::$key1));
     }
+
+    public function testSaveFailsOnNonHashKeyPreservingValueAndTtl(): void
+    {
+        /** @var Redis $redis */
+        $redis = $this->getPrivateProperty($this->handler, 'redis');
+
+        $prefixedKey = $this->config->prefix . 'non_hash_key';
+        $redis->set($prefixedKey, 'raw_string_value');
+        $redis->expire($prefixedKey, 300);
+
+        $this->assertFalse($this->handler->save('non_hash_key', 'new_value', 60));
+
+        $this->assertSame('raw_string_value', $redis->get($prefixedKey));
+        $this->assertGreaterThan(250, $redis->ttl($prefixedKey));
+
+        // Handler remains usable for subsequent operations
+        $this->assertTrue($this->handler->save(self::$key1, 'usable_value'));
+        $this->assertSame('usable_value', $this->handler->get(self::$key1));
+
+        $redis->del($prefixedKey);
+    }
 }