diff --git a/src/core/library/Indexer.cpp b/src/core/library/Indexer.cpp
index e345128e6..68e71804e 100644
--- a/src/core/library/Indexer.cpp
+++ b/src/core/library/Indexer.cpp
@@ -102,7 +102,8 @@ Indexer::Indexer(const std::string& libraryPath, const std::string& dbFilename)
 , tracksScanned(0)
 , exit(false)
 , state(StateIdle)
-, prefs(Preferences::ForComponent(prefs::components::Settings)) {
+, prefs(Preferences::ForComponent(prefs::components::Settings))
+, readSemaphore(prefs->GetInt(prefs::keys::MaxTagReadThreads, MAX_THREADS)) {
     this->metadataReaders = PluginFactory::Instance()
         .QueryInterface<IMetadataReader, MetadataDeleter>("GetMetadataReader");
 
@@ -395,6 +396,10 @@ void Indexer::ReadMetadataFromFile(
     }
 
     this->IncrementTracksScanned();
+
+#ifdef MULTI_THREADED_INDEXER
+    this->readSemaphore.post();
+#endif
 }
 
 inline void Indexer::IncrementTracksScanned(size_t delta) {
@@ -444,6 +449,8 @@ void Indexer::SyncDirectory(
             }
             else {
                 if (io) {
+                    this->readSemaphore.wait();
+
                     io->post(boost::bind(
                         &Indexer::ReadMetadataFromFile,
                         this,
diff --git a/src/core/library/Indexer.h b/src/core/library/Indexer.h
index 136a6a514..016069fe3 100644
--- a/src/core/library/Indexer.h
+++ b/src/core/library/Indexer.h
@@ -48,6 +48,7 @@
 #include <boost/thread/condition.hpp>
 #include <boost/filesystem.hpp>
 #include <boost/asio/io_service.hpp>
+#include <boost/interprocess/sync/interprocess_semaphore.hpp>
 
 #include <deque>
 #include <vector>
@@ -156,6 +157,7 @@ namespace musik { namespace core {
             std::shared_ptr<musik::core::db::ScopedTransaction> trackTransaction;
             std::vector<std::string> paths;
             std::shared_ptr<musik::core::sdk::IIndexerSource> currentSource;
+            boost::interprocess::interprocess_semaphore readSemaphore;
     };
 
     typedef std::shared_ptr<Indexer> IndexerPtr;