diff --git a/src/OpenGL/libGLESv2/Buffer.cpp b/src/OpenGL/libGLESv2/Buffer.cpp
index 0c164fa..c8513cb 100644
--- a/src/OpenGL/libGLESv2/Buffer.cpp
+++ b/src/OpenGL/libGLESv2/Buffer.cpp
@@ -72,7 +72,7 @@
 
 void Buffer::bufferSubData(const void *data, GLsizeiptr size, GLintptr offset)
 {
-	if(mContents)
+	if(mContents && data)
 	{
 		char *buffer = (char*)mContents->lock(sw::PUBLIC);
 		memcpy(buffer + offset, data, size);