diff --git a/src/subtitles_provider_libass.cpp b/src/subtitles_provider_libass.cpp
index 67e06ffcb..70c031405 100644
--- a/src/subtitles_provider_libass.cpp
+++ b/src/subtitles_provider_libass.cpp
@@ -109,6 +109,9 @@ class LibassSubtitlesProvider final : public SubtitlesProvider {
 			return shared->renderer;
 
 		auto block = [&] {
+			if (shared->ready)
+				return;
+			agi::util::sleep_for(250);
 			if (shared->ready)
 				return;
 			br->Run([=](agi::ProgressSink *ps) {