How to prevent window size changes when dragging it?

I have observed that when I move the application window by dragging it, the window size changes. Typically, I prefer my application window to span from the top of the screen to the top of the taskbar. However, I find it bothersome that when I drag the window to one side, its size shrinks. How can I disable this behavior so that the window size remains constant when I drag it towards one side of the screen?