diff --git a/build.gradle.kts b/build.gradle.kts
index 9cd65aa..494adb0 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -57,6 +57,12 @@ tasks {
 	javadoc {
 		options.encoding = "UTF-8"
 	}
+
+	clean {
+		doLast {
+			layout.projectDirectory.dir(".parcel-cache").asFile.deleteRecursively()
+		}
+	}
 }
 
 java {
diff --git a/src/main/frontend/sections/RunControls.tsx b/src/main/frontend/sections/RunControls.tsx
index 5065836..3c54216 100644
--- a/src/main/frontend/sections/RunControls.tsx
+++ b/src/main/frontend/sections/RunControls.tsx
@@ -20,11 +20,12 @@ export const RunControls: FC<{ runWith: (data: FormData) => Promise<void> }> = (
 	async function run(e: FormEvent) {
 		e.preventDefault();
 		const data = new FormData(formRef.current!);
-		data.forEach((val, key) => {
+		for (const key of Array.from(data.keys())) {
+			const val = data.get(key);
 			if (!val || (val instanceof File && !val.name)) {
 				data.delete(key);
 			}
-		});
+		}
 		data.append('_script', JSON.stringify(script));
 
 		await runWith(data);