diff --git a/src/efsw/FileWatcherWin32.cpp b/src/efsw/FileWatcherWin32.cpp
index 5c8d95a..05a20d6 100644
--- a/src/efsw/FileWatcherWin32.cpp
+++ b/src/efsw/FileWatcherWin32.cpp
@@ -144,7 +144,8 @@ void FileWatcherWin32::run() {
 					break;
 				} else {
 					Lock lock( mWatchesLock );
-					WatchCallback( numOfBytes, ov );
+					if (mWatches.find( (WatcherStructWin32*)ov ) != mWatches.end())
+						WatchCallback( numOfBytes, ov );
 				}
 			}
 		} else {
diff --git a/src/efsw/FileWatcherWin32.hpp b/src/efsw/FileWatcherWin32.hpp
index 9cc7d59..3016aac 100644
--- a/src/efsw/FileWatcherWin32.hpp
+++ b/src/efsw/FileWatcherWin32.hpp
@@ -7,7 +7,7 @@
 
 #include <efsw/WatcherWin32.hpp>
 #include <map>
-#include <set>
+#include <unordered_set>
 #include <vector>
 
 namespace efsw {
@@ -17,7 +17,7 @@ namespace efsw {
 class FileWatcherWin32 : public FileWatcherImpl {
   public:
 	/// type for a map from WatchID to WatcherWin32 pointer
-	typedef std::set<WatcherStructWin32*> Watches;
+	typedef std::unordered_set<WatcherStructWin32*> Watches;
 
 	FileWatcherWin32( FileWatcher* parent );
 
diff --git a/src/efsw/WatcherWin32.cpp b/src/efsw/WatcherWin32.cpp
index d47d269..d06cc92 100644
--- a/src/efsw/WatcherWin32.cpp
+++ b/src/efsw/WatcherWin32.cpp
@@ -215,17 +215,14 @@ void DestroyWatch( WatcherStructWin32* pWatch ) {
 		CloseHandle( pWatch->Watch->DirHandle );
 		efSAFE_DELETE_ARRAY( pWatch->Watch->DirName );
 		efSAFE_DELETE( pWatch->Watch );
+		efSAFE_DELETE( pWatch );
 	}
 }
 
 /// Starts monitoring a directory.
 WatcherStructWin32* CreateWatch( LPCWSTR szDirectory, bool recursive,
 								 DWORD bufferSize, DWORD notifyFilter, HANDLE iocp ) {
-	WatcherStructWin32* tWatch;
-	size_t ptrsize = sizeof( *tWatch );
-	tWatch = static_cast<WatcherStructWin32*>(
-		HeapAlloc( GetProcessHeap(), HEAP_ZERO_MEMORY, ptrsize ) );
-
+	WatcherStructWin32* tWatch = new WatcherStructWin32();
 	WatcherWin32* pWatch = new WatcherWin32(bufferSize);
 	if (tWatch)
 		tWatch->Watch = pWatch;
@@ -246,7 +243,7 @@ WatcherStructWin32* CreateWatch( LPCWSTR szDirectory, bool recursive,
 
 	CloseHandle( pWatch->DirHandle );
 	efSAFE_DELETE( pWatch->Watch );
-	HeapFree( GetProcessHeap(), 0, tWatch );
+	efSAFE_DELETE( tWatch );
 	return NULL;
 }