diff --git a/applications/merger/src/main.cpp b/applications/merger/src/main.cpp
index e0abb65efd4b3d911dafe185a1497d82bb9247d4..06d73202f231eca06902f7eb834e10c6aa28fa9b 100644
--- a/applications/merger/src/main.cpp
+++ b/applications/merger/src/main.cpp
@@ -69,6 +69,10 @@ int main(int argc, char **argv) {
 
 		for (size_t j=1; j<rs.size(); ++j) {
 			ftl::codecs::Reader *r = rs[j];
+
+			// FIXME: Need to truncate other stream if the following returns
+			// no frames, meaning the timeshift causes this stream to run out
+			// before the main stream.
 			rs[j]->read(spkt.timestamp+timeoff, [&out,&idmap,&lastid,j,r,stream_mask2,timeoff](const ftl::codecs::StreamPacket &spkt, const ftl::codecs::Packet &pkt) {
 				if (((0x1 << spkt.streamID) & stream_mask2) == 0) return;
 				if (int(spkt.channel) < 32 && spkt.timestamp < r->getStartTime()+timeoff) return;