diff --git a/src/WorldStorage/MapSerializer.cpp b/src/WorldStorage/MapSerializer.cpp
index df72d1cc9..012fc52f3 100644
--- a/src/WorldStorage/MapSerializer.cpp
+++ b/src/WorldStorage/MapSerializer.cpp
@@ -152,6 +152,10 @@ bool cMapSerializer::LoadMapFromNBT(const cParsedNBT & a_NBT)
 	if (CurrLine >= 0)
 	{
 		unsigned int Width = a_NBT.GetShort(CurrLine);
+		if (Width != 128)
+		{
+			return false;
+		}
 		m_Map->m_Width = Width;
 	}
 
@@ -159,6 +163,10 @@ bool cMapSerializer::LoadMapFromNBT(const cParsedNBT & a_NBT)
 	if (CurrLine >= 0)
 	{
 		unsigned int Height = a_NBT.GetShort(CurrLine);
+		if (Height >= 256)
+		{
+			return false;
+		}
 		m_Map->m_Height = Height;
 	}
 
diff --git a/src/WorldStorage/SchematicFileSerializer.cpp b/src/WorldStorage/SchematicFileSerializer.cpp
index d3a708f92..1cf99efd9 100644
--- a/src/WorldStorage/SchematicFileSerializer.cpp
+++ b/src/WorldStorage/SchematicFileSerializer.cpp
@@ -192,7 +192,7 @@ bool cSchematicFileSerializer::LoadFromSchematicNBT(cBlockArea & a_BlockArea, cP
 	int SizeX = a_NBT.GetShort(TSizeX);
 	int SizeY = a_NBT.GetShort(TSizeY);
 	int SizeZ = a_NBT.GetShort(TSizeZ);
-	if ((SizeX < 1) || (SizeY < 1) || (SizeZ < 1))
+	if ((SizeX < 1) || (SizeX > 65535) || (SizeY < 1) || (SizeY > 256) || (SizeZ < 1) || (SizeZ > 65535))
 	{
 		LOG("Dimensions are invalid in the schematic file: %d, %d, %d", SizeX, SizeY, SizeZ);
 		return false;