diff --git a/lib/plugin/analyze.js b/lib/plugin/analyze.js
index 08d2fb96c..7348b48db 100644
--- a/lib/plugin/analyze.js
+++ b/lib/plugin/analyze.js
@@ -155,10 +155,9 @@ const defaultConfig = {
       if (config.vision && test.artifacts.screenshot) {
         debug('Adding screenshot to prompt')
         messages[0].content.push({
-          type: 'image_url',
-          image_url: {
-            url: 'data:image/png;base64,' + base64EncodeFile(test.artifacts.screenshot),
-          },
+          type: 'image',
+          image: base64EncodeFile(test.artifacts.screenshot),
+          mediaType: 'image/png',
         })
       }