diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index 819cee345..956a4453d 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -1245,6 +1245,7 @@ StorePath LocalStore::addToStoreFromDump(
         });
         try {
             got = source.read(dumpBuffer.get() + oldSize, want);
+            if (!got) break;
         } catch (EndOfFile &) {
             inMemory = true;
             break;
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index 2c4dee518..5d6109bae 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -210,14 +210,16 @@ StorePath Store::addToStore(
         fsm = FileSerialisationMethod::NixArchive;
         break;
     }
-    auto source = sinkToSource([&](Sink & sink) {
-        dumpPath(path, sink, fsm, filter);
+    std::optional<StorePath> storePath;
+    auto sink = sourceToSink([&](Source & source) {
+        LengthSource lengthSource(source);
+        storePath = addToStoreFromDump(lengthSource, name, fsm, method, hashAlgo, references, repair);
+        if (lengthSource.total >= settings.warnLargePathThreshold)
+            warn("copied large path '%s' to the store (%s)", path, renderSize(lengthSource.total));
     });
-    LengthSource lengthSource(*source);
-    auto storePath = addToStoreFromDump(lengthSource, name, fsm, method, hashAlgo, references, repair);
-    if (lengthSource.total >= settings.warnLargePathThreshold)
-        warn("copied large path '%s' to the store (%s)", path, renderSize(lengthSource.total));
-    return storePath;
+    dumpPath(path, *sink, fsm, filter);
+    sink->finish();
+    return storePath.value();
 }
 
 void Store::addMultipleToStore(
diff --git a/src/libutil/serialise.cc b/src/libutil/serialise.cc
index 36b99905a..0f2febaed 100644
--- a/src/libutil/serialise.cc
+++ b/src/libutil/serialise.cc
@@ -243,11 +243,11 @@ std::unique_ptr<FinishSink> sourceToSink(std::function<void(Source &)> fun)
             if (!coro) {
                 CoroutineContext ctx;
                 coro = coro_t::push_type(VirtualStackAllocator{}, [&](coro_t::pull_type & yield) {
-                    LambdaSource source([&](char *out, size_t out_len) {
+                    LambdaSource source([&](char * out, size_t out_len) {
                         if (cur.empty()) {
                             yield();
                             if (yield.get()) {
-                                return (size_t)0;
+                                return (size_t) 0;
                             }
                         }
 
@@ -271,12 +271,12 @@ std::unique_ptr<FinishSink> sourceToSink(std::function<void(Source &)> fun)
         void finish() override
         {
             if (!coro) return;
-            if (!*coro) abort();
+            //if (!*coro) abort();
             {
                 CoroutineContext ctx;
                 (*coro)(true);
             }
-            if (*coro) abort();
+            //if (*coro) abort();
         }
     };