diff --git a/source/shared_lib/sources/map/map_preview.cpp b/source/shared_lib/sources/map/map_preview.cpp
index e8cd70c3..761f69ea 100644
--- a/source/shared_lib/sources/map/map_preview.cpp
+++ b/source/shared_lib/sources/map/map_preview.cpp
@@ -755,6 +755,7 @@ void MapPreview::saveToFile(const string &path) {
 
 		//write header
 		MapFileHeader header;
+		memset(&header,0,sizeof(header));
 
 		header.version = MAP_FORMAT_VERSION;
 		header.maxFactions = maxFactions;