diff --git a/public/scripts/extensions/stable-diffusion/index.js b/public/scripts/extensions/stable-diffusion/index.js
index e8bc8f1e2..15e8736b0 100644
--- a/public/scripts/extensions/stable-diffusion/index.js
+++ b/public/scripts/extensions/stable-diffusion/index.js
@@ -2286,7 +2286,7 @@ async function generateComfyImage(prompt, negativePrompt) {
         toastr.error(`Failed to load workflow.\n\n${text}`);
     }
     let workflow = (await workflowResponse.json()).replace('"%prompt%"', JSON.stringify(prompt));
-    workflow = (await workflowResponse.json()).replace('"%negative_prompt%"', JSON.stringify(negativePrompt));
+    workflow = workflow.replace('"%negative_prompt%"', JSON.stringify(negativePrompt));
     workflow = workflow.replace('"%seed%"', JSON.stringify(Math.round(Math.random() * Number.MAX_SAFE_INTEGER)));
     placeholders.forEach(ph => {
         workflow = workflow.replace(`"%${ph}%"`, JSON.stringify(extension_settings.sd[ph]));