diff --git a/src/protocol.test.ts b/src/protocol.test.ts
index d886cc0..22b1eac 100644
--- a/src/protocol.test.ts
+++ b/src/protocol.test.ts
@@ -122,6 +122,13 @@ describe('parseCommand', () => {
       const result = parseCommand(cmd({ id: '1', action: 'screenshot', fullPage: true }));
       expect(result.success).toBe(true);
     });
+
+    it('should parse screenshot with null selector', () => {
+      const result = parseCommand(
+        cmd({ id: '1', action: 'screenshot', path: 'test.png', selector: null })
+      );
+      expect(result.success).toBe(true);
+    });
   });
 
   describe('cookies', () => {
diff --git a/src/protocol.ts b/src/protocol.ts
index 4e13e2c..8f899eb 100644
--- a/src/protocol.ts
+++ b/src/protocol.ts
@@ -693,7 +693,7 @@ const screenshotSchema = baseCommandSchema.extend({
   action: z.literal('screenshot'),
   path: z.string().nullable().optional(),
   fullPage: z.boolean().optional(),
-  selector: z.string().min(1).optional(),
+  selector: z.string().min(1).nullish(),
   format: z.enum(['png', 'jpeg']).optional(),
   quality: z.number().min(0).max(100).optional(),
 });