diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 03d977c..90c2512 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,10 @@ jobs:
           path: /tmp/composer-cache
           key: ${{ runner.os }}-${{ hashFiles('**/composer.lock') }}
 
-      - uses: php-actions/composer@v6
+      - name: Composer
+        uses: php-actions/composer@v6
+        with:
+          php_version: 8.1
 
       - name: Archive build
         run: mkdir /tmp/github-actions/ && tar -cvf /tmp/github-actions/build.tar ./
diff --git a/composer.json b/composer.json
index e984106..ab2a9e7 100644
--- a/composer.json
+++ b/composer.json
@@ -3,7 +3,7 @@
 	"description": " Structured, type-safe, immutable JSON objects.",
 
 	"require": {
-		"php": ">=8.0",
+		"php": ">=8.1",
 		"ext-json": "*",
 
 		"phpgt/dataobject": "^1.0"
diff --git a/composer.lock b/composer.lock
index 096317e..90059db 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "8f48b785533048a61d02f7e70c650982",
+    "content-hash": "7f8afeff72fc2fd8f7dd8e7558b14302",
     "packages": [
         {
             "name": "phpgt/dataobject",
@@ -1902,7 +1902,7 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": ">=8.0",
+        "php": ">=8.1",
         "ext-json": "*"
     },
     "platform-dev": [],
diff --git a/src/JsonObjectBuilder.php b/src/JsonObjectBuilder.php
index 6304e9b..f845b4d 100644
--- a/src/JsonObjectBuilder.php
+++ b/src/JsonObjectBuilder.php
@@ -9,6 +9,7 @@
 use Gt\Json\JsonPrimitive\JsonNullPrimitive;
 use Gt\Json\JsonPrimitive\JsonPrimitive;
 use Gt\Json\JsonPrimitive\JsonStringPrimitive;
+use JsonException as NativeJsonException;
 use stdClass;
 
 class JsonObjectBuilder extends DataObjectBuilder {
@@ -18,13 +19,15 @@ public function __construct(
 	}
 
 	public function fromJsonString(string $jsonString):JsonObject {
-		$json = json_decode($jsonString, depth: $this->depth);
-		if(is_null($json)) {
-// It's completely reasonable to have a null value here, so we need to check the
-// error code before throwing an exception.
-			if(json_last_error() !== JSON_ERROR_NONE) {
-				throw new JsonDecodeException(json_last_error_msg());
-			}
+		try {
+			$json = json_decode(
+				$jsonString,
+				depth: $this->depth,
+				flags: JSON_THROW_ON_ERROR
+			);
+		}
+		catch(NativeJsonException $exception) {
+			throw new JsonDecodeException($exception->getMessage());
 		}
 
 		return $this->fromJsonDecoded($json);