That's the way mine is. I removed the sticker on the base though as it becomes submerged and scrubbed all the remaining glue off. I wasn't sure if there was anything in the sticker that might cause an issue but I didn't want to chance it.
I think my tank is several years old and the plastic frame is not of typical dimmensions. No matter how I try, I can't fit the base of the light over the rim while keeping any stability. The piece that fts against the tank seems too big to fit but without it, I only have the 2 screws pressed against the rim which leaves huge pressure points and no stability.