Gparted doesn’t let me extend partition?

My disk looks as follows:

/dev/sdc1  *      2048    499711    497664   243M 83 Linux
/dev/sdc2       501758 234440703 233938946 111,6G  5 Extended
/dev/sdc5       501760 234440703 233938944 111,6G 8e Linux LVM

I would like to close the gap between sdc1 and sdc2 by extending boot partition sdc1.
However, gparted doesn’t allow me to drag the boundaries of said partition, like there is no space. Yes, the partition is unmounted, and I’m running from a live CD.

What is going on here?