diff --git a/src/libstore/filetransfer.cc b/src/libstore/filetransfer.cc
index 756bd4423..2818043e8 100644
--- a/src/libstore/filetransfer.cc
+++ b/src/libstore/filetransfer.cc
@@ -828,16 +828,15 @@ void FileTransfer::download(FileTransferRequest && request, Sink & sink)
         {
             auto state(_state->lock());
 
-            while (state->data.empty()) {
-
-                if (state->quit) {
-                    if (state->exc) std::rethrow_exception(state->exc);
-                    return;
-                }
-
-                state.wait(state->avail);
+            if (state->quit) {
+                if (state->exc) std::rethrow_exception(state->exc);
+                return;
             }
 
+            state.wait(state->avail);
+
+            if (state->data.empty()) continue;
+
             chunk = std::move(state->data);
 
             state->request.notify_one();