3 files changed, 21 insertions, 3 deletions
diff --git a/packages/renderers/renderer-preact/index.js b/packages/renderers/renderer-preact/index.js
index 84d2021d1..5819ab0f2 100644
--- a/packages/renderers/renderer-preact/index.js
+++ b/packages/renderers/renderer-preact/index.js
@@ -2,5 +2,14 @@ export default {
   name: '@astrojs/renderer-preact',
   client: './client',
   server: './server',
-  knownEntrypoints: ['preact', 'preact-render-to-string'],
+  knownEntrypoints: ['preact', 'preact/jsx-runtime', 'preact-render-to-string'],
+  jsxImportSource: 'preact',
+  jsxTransformOptions: async () => {
+    const { default: { default: jsx }} = await import('@babel/plugin-transform-react-jsx');
+    return {
+      plugins: [
+        jsx({}, { runtime: 'automatic', importSource: 'preact' })
+      ]
+    }
+  }
 };
diff --git a/packages/renderers/renderer-preact/package.json b/packages/renderers/renderer-preact/package.json
index f22560afb..a81097011 100644
--- a/packages/renderers/renderer-preact/package.json
+++ b/packages/renderers/renderer-preact/package.json
@@ -10,7 +10,8 @@
   },
   "dependencies": {
     "preact": "^10.5.13",
-    "preact-render-to-string": "^5.1.18"
+    "preact-render-to-string": "^5.1.18",
+    "@babel/plugin-transform-react-jsx": "^7.14.5"
   },
   "engines": {
     "node": "^12.20.0 || ^14.13.1 || >=16.0.0"
diff --git a/packages/renderers/renderer-preact/server.js b/packages/renderers/renderer-preact/server.js
index ac8661a49..441ce8ef0 100644
--- a/packages/renderers/renderer-preact/server.js
+++ b/packages/renderers/renderer-preact/server.js
@@ -10,7 +10,15 @@ function check(Component, props, children) {
   }
 
   const { html } = renderToStaticMarkup(Component, props, children);
-  return typeof html === 'string';
+
+  if (typeof html !== 'string') {
+    return false;
+  }
+
+  // There are edge cases (SolidJS) where Preact *might* render a string,
+  // but components would be <undefined></undefined>
+
+  return !/\<undefined\>/.test(html);
 }
 
 function renderToStaticMarkup(Component, props, children) {