How do I prevent font resizing in the debugger console pane?

On my Mac OS X, if I drag two fingers on the mouse pad up or down then the debug console pane scrolls up or down.  If I hold the command key while doing this, the debug console font shrinks or grows, which is very annoying.  Frequently I will use the two-finger mouse drag to scroll the console pane and if I do this fast enough, it will continue to scroll even after I take my fingers off the mouse pad; a sort of scrolling inertia.  Then I press the command key and the font shrinks.

Is there a way to prevent the debug console font resizing this way?