diff --git a/src/tools/map_extract.cpp b/src/tools/map_extract.cpp
index 664442404..5c2c5a799 100644
--- a/src/tools/map_extract.cpp
+++ b/src/tools/map_extract.cpp
@@ -9,40 +9,39 @@
 
 bool Process(IStorage *pStorage, const char *pMapName, const char *pPathSave)
 {
-	CDataFileReader Map;
-
-	if(!Map.Open(pStorage, pMapName, IStorage::TYPE_ABSOLUTE))
+	CDataFileReader Reader;
+	if(!Reader.Open(pStorage, pMapName, IStorage::TYPE_ABSOLUTE))
 	{
 		dbg_msg("map_extract", "error opening map '%s'", pMapName);
 		return false;
 	}
 
 	// check version
-	CMapItemVersion *pVersion = (CMapItemVersion *)Map.FindItem(MAPITEMTYPE_VERSION, 0);
+	CMapItemVersion *pVersion = (CMapItemVersion *)Reader.FindItem(MAPITEMTYPE_VERSION, 0);
 	if(pVersion && pVersion->m_Version != 1)
 		return false;
 
 	dbg_msg("map_extract", "Make sure you have the permission to use these images and sounds in your own maps");
 
-	CMapItemInfo *pInfo = (CMapItemInfo *)Map.FindItem(MAPITEMTYPE_INFO, 0);
+	CMapItemInfo *pInfo = (CMapItemInfo *)Reader.FindItem(MAPITEMTYPE_INFO, 0);
 
 	if(pInfo)
 	{
-		dbg_msg("map_extract", "author:  %s", (char *)Map.GetData(pInfo->m_Author));
-		dbg_msg("map_extract", "version: %s", (char *)Map.GetData(pInfo->m_MapVersion));
-		dbg_msg("map_extract", "credits: %s", (char *)Map.GetData(pInfo->m_Credits));
-		dbg_msg("map_extract", "license: %s", (char *)Map.GetData(pInfo->m_License));
+		dbg_msg("map_extract", "author:  %s", (char *)Reader.GetData(pInfo->m_Author));
+		dbg_msg("map_extract", "version: %s", (char *)Reader.GetData(pInfo->m_MapVersion));
+		dbg_msg("map_extract", "credits: %s", (char *)Reader.GetData(pInfo->m_Credits));
+		dbg_msg("map_extract", "license: %s", (char *)Reader.GetData(pInfo->m_License));
 	}
 
 	int Start, Num;
 
 	// load images
-	Map.GetType(MAPITEMTYPE_IMAGE, &Start, &Num);
+	Reader.GetType(MAPITEMTYPE_IMAGE, &Start, &Num);
 
 	for(int i = 0; i < Num; i++)
 	{
-		CMapItemImage *pItem = (CMapItemImage *)Map.GetItem(Start + i, 0, 0);
-		char *pName = (char *)Map.GetData(pItem->m_ImageName);
+		CMapItemImage *pItem = (CMapItemImage *)Reader.GetItem(Start + i, nullptr, nullptr);
+		char *pName = (char *)Reader.GetData(pItem->m_ImageName);
 
 		if(pItem->m_External)
 			continue;
@@ -66,18 +65,18 @@ bool Process(IStorage *pStorage, const char *pMapName, const char *pPathSave)
 		}
 		else
 		{
-			png_set_data(&Png, pItem->m_Width, pItem->m_Height, 8, PNG_TRUECOLOR_ALPHA, (unsigned char *)Map.GetData(pItem->m_ImageData));
+			png_set_data(&Png, pItem->m_Width, pItem->m_Height, 8, PNG_TRUECOLOR_ALPHA, (unsigned char *)Reader.GetData(pItem->m_ImageData));
 		}
 		io_close(File);
 	}
 
 	// load sounds
-	Map.GetType(MAPITEMTYPE_SOUND, &Start, &Num);
+	Reader.GetType(MAPITEMTYPE_SOUND, &Start, &Num);
 
 	for(int i = 0; i < Num; i++)
 	{
-		CMapItemSound *pItem = (CMapItemSound *)Map.GetItem(Start + i, 0, 0);
-		char *pName = (char *)Map.GetData(pItem->m_SoundName);
+		CMapItemSound *pItem = (CMapItemSound *)Reader.GetItem(Start + i, nullptr, nullptr);
+		char *pName = (char *)Reader.GetData(pItem->m_SoundName);
 
 		if(pItem->m_External)
 			continue;
@@ -87,11 +86,11 @@ bool Process(IStorage *pStorage, const char *pMapName, const char *pPathSave)
 		dbg_msg("map_extract", "writing sound: %s (%d B)", aBuf, pItem->m_SoundDataSize);
 
 		IOHANDLE Opus = io_open(aBuf, IOFLAG_WRITE);
-		io_write(Opus, (unsigned char *)Map.GetData(pItem->m_SoundData), pItem->m_SoundDataSize);
+		io_write(Opus, (unsigned char *)Reader.GetData(pItem->m_SoundData), pItem->m_SoundDataSize);
 		io_close(Opus);
 	}
 
-	return Map.Close();
+	return Reader.Close();
 }
 
 int main(int argc, const char *argv[])
@@ -99,20 +98,18 @@ int main(int argc, const char *argv[])
 	cmdline_fix(&argc, &argv);
 	log_set_global_logger_default();
 
-	char aMap[512];
-	char aDir[512];
-
 	IStorage *pStorage = CreateLocalStorage();
+	if(!pStorage)
+		return -1;
 
+	const char *pDir;
 	if(argc == 2)
 	{
-		str_copy(aMap, argv[1], sizeof(aMap));
-		str_copy(aDir, ".", sizeof(aMap));
+		pDir = ".";
 	}
 	else if(argc == 3)
 	{
-		str_copy(aMap, argv[1], sizeof(aMap));
-		str_copy(aDir, argv[2], sizeof(aDir));
+		pDir = argv[2];
 	}
 	else
 	{
@@ -120,15 +117,15 @@ int main(int argc, const char *argv[])
 		return -1;
 	}
 
-	if(!fs_is_dir(aDir))
+	if(!fs_is_dir(pDir))
 	{
-		dbg_msg("usage", "directory '%s' does not exist", aDir);
+		dbg_msg("usage", "directory '%s' does not exist", pDir);
 		return -1;
 	}
 
 	png_init(0, 0);
 
-	int Result = Process(pStorage, aMap, aDir) ? 0 : 1;
+	int Result = Process(pStorage, argv[1], pDir) ? 0 : 1;
 	cmdline_free(argc, argv);
 	return Result;
 }