diff --git a/tests/Protocol/FormatTest.php b/tests/Protocol/FormatTest.php
index 5b8b23f5f..9fd757672 100644
--- a/tests/Protocol/FormatTest.php
+++ b/tests/Protocol/FormatTest.php
@@ -15,6 +15,14 @@ public function test_rejects_bad_accept_subtype()
         );
     }
 
+    public function test_no_accept_header()
+    {
+        $this->assertResponseSnapshot(
+            (new Request)
+                ->unsetHeader('accept')
+        );
+    }
+
     public function test_rejects_bad_accept_type_subtype()
     {
         $this->assertNotAcceptable(
diff --git a/tests/__snapshots__/Protocol/FormatTest__test_no_accept_header__1.yml b/tests/__snapshots__/Protocol/FormatTest__test_no_accept_header__1.yml
new file mode 100644
index 000000000..7a16a321e
--- /dev/null
+++ b/tests/__snapshots__/Protocol/FormatTest__test_no_accept_header__1.yml
@@ -0,0 +1,5 @@
+headers:
+    cache-control: ['no-cache, private']
+    content-type: [application/json;metadata=minimal]
+    odata-version: ['4.01']
+status: 200