diff --git a/packages/fern-docs/ui/src/playground/fetch-utils/requestToBodyInit.ts b/packages/fern-docs/ui/src/playground/fetch-utils/requestToBodyInit.ts
index deab01c6ac..6072a89764 100644
--- a/packages/fern-docs/ui/src/playground/fetch-utils/requestToBodyInit.ts
+++ b/packages/fern-docs/ui/src/playground/fetch-utils/requestToBodyInit.ts
@@ -15,15 +15,23 @@ export async function toBodyInit(
       for (const [key, value] of Object.entries(body.value)) {
         switch (value.type) {
           case "json": {
-            if (value.value !== undefined) {
+            if (value.value === undefined) {
+              break;
+            }
+            if (value.contentType === "application/json") {
               formData.append(
                 key,
-                value.contentType
-                  ? new Blob([JSON.stringify(value.value)], {
-                      type: value.contentType,
-                    })
-                  : JSON.stringify(value.value)
+                new Blob([JSON.stringify(value.value)], {
+                  type: "application/json",
+                })
               );
+            } else {
+              const finalValue =
+                typeof value.value === "string"
+                  ? value.value
+                  : JSON.stringify(value.value);
+
+              formData.append(key, finalValue);
             }
             break;
           }