diff --git a/packages/plugin-adapter-netlify/src/index.js b/packages/plugin-adapter-netlify/src/index.js
index 7336f174f..992304c47 100644
--- a/packages/plugin-adapter-netlify/src/index.js
+++ b/packages/plugin-adapter-netlify/src/index.js
@@ -18,10 +18,12 @@ function generateOutputFormat(id) {
       if (['GET', 'HEAD'].includes(httpMethod.toUpperCase())) {
         format = null
       } else if (contentType.includes('application/x-www-form-urlencoded')) {
+        const searchParams = new URLSearchParams(body);
         const formData = new FormData();
 
-        for (const key of Object.keys(body)) {
-          formData.append(key, body[key]);
+        for (const key of searchParams.keys()) {
+          const value = searchParams.get(key);
+          formData.append(key, value);
         }
 
         // when using FormData, let Request set the correct headers
diff --git a/packages/plugin-adapter-netlify/test/cases/build.default/build.default.spec.js b/packages/plugin-adapter-netlify/test/cases/build.default/build.default.spec.js
index a51f5c69f..e93209128 100644
--- a/packages/plugin-adapter-netlify/test/cases/build.default/build.default.spec.js
+++ b/packages/plugin-adapter-netlify/test/cases/build.default/build.default.spec.js
@@ -215,7 +215,7 @@ describe('Build Greenwood With: ', function() {
         const { handler } = await import(new URL(`./${name}/${name}.js`, netlifyFunctionsOutputUrl));
         const response = await handler({
           rawUrl: 'http://localhost:8080/api/submit-form-data',
-          body: { name: param },
+          body: `name=${param}`,
           httpMethod: 'POST',
           headers: {
             'content-type': 'application/x-www-form-urlencoded'