diff --git a/codegen/pkg/generator/sumup.go b/codegen/pkg/generator/sumup.go
index a440ec4..9e6cedd 100644
--- a/codegen/pkg/generator/sumup.go
+++ b/codegen/pkg/generator/sumup.go
@@ -142,6 +142,7 @@ class SumUp
         }
 
         $headers = is_array($config['custom_headers']) ? $config['custom_headers'] : [];
+        $headers['Accept'] = 'application/problem+json, application/json';
         $headers['User-Agent'] = SdkInfo::getUserAgent();
         $config['custom_headers'] = $headers;
 
diff --git a/src/SumUp.php b/src/SumUp.php
index ba6db6e..283170b 100644
--- a/src/SumUp.php
+++ b/src/SumUp.php
@@ -149,6 +149,7 @@ private function normalizeConfig(array $config): array
         }
 
         $headers = is_array($config['custom_headers']) ? $config['custom_headers'] : [];
+        $headers['Accept'] = 'application/problem+json, application/json';
         $headers['User-Agent'] = SdkInfo::getUserAgent();
         $config['custom_headers'] = $headers;
 
diff --git a/tests/SdkInfoTest.php b/tests/SdkInfoTest.php
index df8c602..d614960 100644
--- a/tests/SdkInfoTest.php
+++ b/tests/SdkInfoTest.php
@@ -10,10 +10,15 @@ class SdkInfoTest extends TestCase
 {
     public function testStandardHeadersIncludeRuntimeMetadata()
     {
-        $headers = ['Content-Type' => 'application/json', 'User-Agent' => SdkInfo::getUserAgent()];
+        $headers = [
+            'Content-Type' => 'application/json',
+            'Accept' => 'application/problem+json, application/json',
+            'User-Agent' => SdkInfo::getUserAgent(),
+        ];
         $headers = array_merge($headers, SdkInfo::getRuntimeHeaders());
 
         $this->assertSame('application/json', $headers['Content-Type']);
+        $this->assertSame('application/problem+json, application/json', $headers['Accept']);
         $this->assertSame(SdkInfo::getUserAgent(), $headers['User-Agent']);
         $this->assertSame(ApiVersion::CURRENT, $headers['X-Sumup-Api-Version']);
         $this->assertSame('php', $headers['X-Sumup-Lang']);