diff --git a/QtMeshViewer/Source/MshFile.cpp b/QtMeshViewer/Source/MshFile.cpp
index b654c5c..22f11cc 100644
--- a/QtMeshViewer/Source/MshFile.cpp
+++ b/QtMeshViewer/Source/MshFile.cpp
@@ -272,7 +272,7 @@ void MshFile::analyseMatdChunks(std::list<ChunkHeader*>& chunkList)
 			// 7: specular
 
 			for (unsigned int i = 0; i < 8; i++)
-				m_materials->back().flags[i] = (flag << (7 - i)) >> 7;
+				m_materials->back().flags[i] = (std::uint8_t)(flag << (7 - i)) >> 7;
 
 			m_materials->back().transparent = m_materials->back().flags[2] || m_materials->back().flags[3] || m_materials->back().flags[4] || m_materials->back().flags[6];