diff --git a/src/app/api/generate/__tests__/route.test.ts b/src/app/api/generate/__tests__/route.test.ts
index 4a288549..7048ae1d 100644
--- a/src/app/api/generate/__tests__/route.test.ts
+++ b/src/app/api/generate/__tests__/route.test.ts
@@ -1096,6 +1096,10 @@ describe("/api/generate route", () => {
         aspectRatio: "9:16",
         imageSize: "2K",
       });
+      expect(body.generationConfig.responseFormat.image).toMatchObject({
+        aspectRatio: "9:16",
+        imageSize: "2K",
+      });
     });
   });
 
diff --git a/src/app/api/generate/providers/__tests__/newapiwg.test.ts b/src/app/api/generate/providers/__tests__/newapiwg.test.ts
index 96cf2cc8..8bcd9079 100644
--- a/src/app/api/generate/providers/__tests__/newapiwg.test.ts
+++ b/src/app/api/generate/providers/__tests__/newapiwg.test.ts
@@ -265,6 +265,9 @@ describe("NewApiWG generation payloads", () => {
     expect(capturedBody!.generationConfig).toMatchObject({
       responseModalities: ["IMAGE"],
       imageConfig: { aspectRatio: "1:1", imageSize: "2K" },
+      responseFormat: {
+        image: { aspectRatio: "1:1", imageSize: "2K" },
+      },
     });
   });
 
diff --git a/src/app/api/generate/providers/newapiwg.ts b/src/app/api/generate/providers/newapiwg.ts
index 81253cfc..72828c43 100644
--- a/src/app/api/generate/providers/newapiwg.ts
+++ b/src/app/api/generate/providers/newapiwg.ts
@@ -856,6 +856,12 @@ async function generateImageViaNewApiWGGemini(
           aspectRatio,
           imageSize,
         },
+        responseFormat: {
+          image: {
+            aspectRatio,
+            imageSize,
+          },
+        },
       },
       ...dynamicInputsWithoutPrompt(input),
     }),