diff --git a/src/integrations/misc/__tests__/imageDataUrl.spec.ts b/src/integrations/misc/__tests__/imageDataUrl.spec.ts
index 01b100afa8..0ebce80b08 100644
--- a/src/integrations/misc/__tests__/imageDataUrl.spec.ts
+++ b/src/integrations/misc/__tests__/imageDataUrl.spec.ts
@@ -18,6 +18,33 @@ describe("normalizeImageRefsToDataUrls", () => {
 		expect(result).toEqual([dataUrl])
 	})
 
+	it("should convert CDN webview URIs to data URLs", async () => {
+		const cdnUri = "https://file+.vscode-resource.vscode-cdn.net/path/to/test.png"
+		const mockBuffer = Buffer.from("test image data")
+
+		vi.mocked(fs.readFile).mockResolvedValue(mockBuffer)
+
+		const result = await normalizeImageRefsToDataUrls([cdnUri])
+
+		expect(result).toHaveLength(1)
+		expect(result[0]).toMatch(/^data:image\/png;base64,/)
+		expect(fs.readFile).toHaveBeenCalledWith("/path/to/test.png")
+	})
+
+	it("should handle mixed arrays of data URLs and CDN URIs", async () => {
+		const dataUrl = "data:image/jpeg;base64,test123"
+		const cdnUri = "https://file+.vscode-resource.vscode-cdn.net/path/to/test.png"
+		const mockBuffer = Buffer.from("test image data")
+
+		vi.mocked(fs.readFile).mockResolvedValue(mockBuffer)
+
+		const result = await normalizeImageRefsToDataUrls([dataUrl, cdnUri])
+
+		expect(result).toHaveLength(2)
+		expect(result[0]).toBe(dataUrl) // Data URL unchanged
+		expect(result[1]).toMatch(/^data:image\/png;base64,/) // CDN URI converted
+	})
+
 	it("should handle errors gracefully by skipping problematic images", async () => {
 		const validDataUrl = "data:image/png;base64,valid"
 		const invalidCdnUri = "vscode-file://vscode-app/nonexistent/test.png"