diff --git a/tools/deploy/index.ts b/tools/deploy/index.ts
index ded1e5bf..4c6a2812 100644
--- a/tools/deploy/index.ts
+++ b/tools/deploy/index.ts
@@ -36,8 +36,13 @@ program
 
         for (const file of files) {
             const src = pathlib.path(file);
-            const result = scr.runOnFile(src);
-            const dst = pathlib.join(outputDir, pathlib.path(src, result));
+            const input = pathlib.update(src, {dir: ""});
+            const result = scr.runOnFile(input);
+            if (result === undefined) {
+                throw new Error(`undefined output on ${file}`);
+            }
+            const output = pathlib.path(input, result);
+            const dst = pathlib.join(outputDir, output);
             aq.copy(src, dst);
         }