Charlize Theron is ''so happy'' to be turning 40 next month.

The 'Mad Max: Fury Road' star, who split from Sean Penn in May after 18 months of dating, insists she isn't dreading her upcoming milestone birthday on August 7.

She said: ''Forties rock. People are so concerned for me. It's okay. It's such a weird thing that we put so much... I think especially for women. I'm so happy to be in my 40s and not be in my 20s and worried about whether I fit into my skinny jeans or whether I will be able to get into that club. It's just so nice to be in love with your couch and make cheesy sandwiches and just enjoy life, it's been great.''

The 'Dark Places' star, who has three-year-old son Jackson, also claims she has no special plans in place to mark the occasion.

Asked how she is planning to celebrate, the blonde beauty told E! News: ''I don't know. I honestly haven't even been thinking about it. I just literally wrapped a movie two days ago, I have not thought of it, I'm leaving town in two days. I've never been a big birthday person. I find myself, I'll celebrate a month later if I'm in the right place or the right restaurant, like, [I'll shout] 'You guys, tonight's my birthday.' ''