diff --git a/src/runtime/webcore/Blob.zig b/src/runtime/webcore/Blob.zig
index 6cf5c0475545..4f9f8173887b 100644
--- a/src/runtime/webcore/Blob.zig
+++ b/src/runtime/webcore/Blob.zig
@@ -2975,7 +2975,19 @@ pub fn getWriter(
 
     if (arguments.len > 0 and arguments.ptr[0].isObject()) {
         stream_start = try jsc.WebCore.streams.Start.fromJSWithTag(globalThis, arguments[0], .FileSink);
-        stream_start.FileSink.input_path = input_path;
+        switch (stream_start) {
+            .FileSink => |*file_sink| {
+                file_sink.input_path.deinit();
+                file_sink.input_path = input_path;
+            },
+            .err => |err| {
+                sink.deref();
+                return globalThis.throwValue(try err.toJS(globalThis));
+            },
+            else => {
+                stream_start = .{ .FileSink = .{ .input_path = input_path } };
+            },
+        }
     }
 
     switch (sink.start(stream_start)) {
diff --git a/test/js/bun/util/filesink.test.ts b/test/js/bun/util/filesink.test.ts
index 736e5b085731..e09733a17c9b 100644
--- a/test/js/bun/util/filesink.test.ts
+++ b/test/js/bun/util/filesink.test.ts
@@ -268,3 +268,13 @@ it.skipIf(!isPosix)("does not leak native FileSink when a pending write fails (E
   // more than that indicates a native leak.
   expect(fileSinkInternals.liveCount()).toBeLessThanOrEqual(baseline + 1);
 });
+
+it("writer() throws instead of crashing when options has a non-string path", () => {
+  const file = Bun.file(join(tmpdirSync(), "writer-invalid-path.txt"));
+  expect(() => file.writer({ path: Int32Array } as any)).toThrow();
+});
+
+it("writer() throws instead of crashing when options has an invalid fd", () => {
+  const file = Bun.file(join(tmpdirSync(), "writer-invalid-fd.txt"));
+  expect(() => file.writer({ fd: "not-a-number" } as any)).toThrow();
+});