diff --git a/source/Irrlicht/COpenGLDriver.cpp b/source/Irrlicht/COpenGLDriver.cpp
index 26757923..0ae5a86f 100644
--- a/source/Irrlicht/COpenGLDriver.cpp
+++ b/source/Irrlicht/COpenGLDriver.cpp
@@ -804,7 +804,7 @@ IRenderTarget* COpenGLDriver::addRenderTarget()
 
 
 // small helper function to create vertex buffer object address offsets
-static inline const GLvoid * buffer_offset(const long offset)
+static inline const GLvoid * buffer_offset(const size_t offset)
 {
 	return (const GLvoid *)offset;
 }