diff --git a/composer.json b/composer.json
index 6ae3318..c568aad 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
     "require": {
         "ext-grpc": "*",
         "grpc/grpc": "1.22",
-        "google/protobuf": "3.8.0"
+        "google/protobuf": "4.33.6"
     },
     "config": {
         "bin-dir": "bin"
diff --git a/composer.lock b/composer.lock
index b5d6dbb..b922267 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,27 +4,27 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "df4f984436c2492acc305611aec8a578",
+    "content-hash": "1d1b0e22a9edb987e4c04e013d26a0bf",
     "packages": [
         {
             "name": "google/protobuf",
-            "version": "v3.8.0",
+            "version": "v4.33.6",
             "source": {
                 "type": "git",
                 "url": "https://github.com/protocolbuffers/protobuf-php.git",
-                "reference": "a257235dc1a0d45f8cfc641d0c2ad852f57396c4"
+                "reference": "84b008c23915ed94536737eae46f41ba3bccfe67"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/protocolbuffers/protobuf-php/zipball/a257235dc1a0d45f8cfc641d0c2ad852f57396c4",
-                "reference": "a257235dc1a0d45f8cfc641d0c2ad852f57396c4",
+                "url": "https://api.github.com/repos/protocolbuffers/protobuf-php/zipball/84b008c23915ed94536737eae46f41ba3bccfe67",
+                "reference": "84b008c23915ed94536737eae46f41ba3bccfe67",
                 "shasum": ""
             },
             "require": {
-                "php": ">=5.5.0"
+                "php": ">=8.1.0"
             },
             "require-dev": {
-                "phpunit/phpunit": ">=4.8.0"
+                "phpunit/phpunit": ">=10.5.62 <11.0.0"
             },
             "suggest": {
                 "ext-bcmath": "Need to support JSON deserialization"
@@ -45,7 +45,10 @@
             "keywords": [
                 "proto"
             ],
-            "time": "2019-05-29T00:06:29+00:00"
+            "support": {
+                "source": "https://github.com/protocolbuffers/protobuf-php/tree/v4.33.6"
+            },
+            "time": "2026-03-18T17:32:05+00:00"
         },
         {
             "name": "grpc/grpc",
@@ -92,11 +95,12 @@
     "packages-dev": [],
     "aliases": [],
     "minimum-stability": "stable",
-    "stability-flags": [],
+    "stability-flags": {},
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
         "ext-grpc": "*"
     },
-    "platform-dev": []
+    "platform-dev": {},
+    "plugin-api-version": "2.9.0"
 }