diff --git a/package.json b/package.json
index d375f98..56d26e0 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "koishi-plugin-novelai",
   "description": "Generate images by NovelAI",
-  "version": "1.12.1",
+  "version": "1.12.2",
   "main": "lib/index.js",
   "typings": "lib/index.d.ts",
   "files": [
diff --git a/src/index.ts b/src/index.ts
index c5df61d..cd1c24d 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,7 +1,7 @@
 import { Context, Dict, Logger, omit, Quester, segment, Session, trimSlash } from 'koishi'
 import { Config, modelMap, models, orientMap, parseForbidden, parseInput, sampler } from './config'
 import { StableDiffusionWebUI } from './types'
-import { closestMultiple, download, getImageSize, login, NetworkError, project, resizeInput, Size } from './utils'
+import { closestMultiple, download, getImageSize, login, NetworkError, project, resizeInput, Size, stripDataPrefix } from './utils'
 import {} from '@koishijs/plugin-help'
 
 export * from './config'
@@ -255,12 +255,12 @@ export function apply(ctx: Context, config: Config) {
         data,
       }).then((res) => {
         if (config.type === 'sd-webui') {
-          return (res.data as StableDiffusionWebUI.Response).images[0]
+          return stripDataPrefix((res.data as StableDiffusionWebUI.Response).images[0])
         }
         // event: newImage
         // id: 1
         // data:
-        return res.data.slice(27)
+        return res.data?.slice(27)
       })
 
       let base64: string, count = 0
diff --git a/src/utils.ts b/src/utils.ts
index 9c20dca..717daeb 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -185,3 +185,9 @@ export function resizeInput(size: Size): Size {
     return { width, height }
   }
 }
+
+export function stripDataPrefix(base64: string) {
+  // workaround for different gradio versions
+  // https://github.com/koishijs/novelai-bot/issues/90
+  return base64.replace(/^data:image\/[\w-]+;base64,/, '')
+}