In some surprising box office news, The Avengers: Age of Ultron has ended up with lower than expected opening weekend numbers. The film tallied $187 million at the U.S. box office, making it the #2 movie behind The Avengers at the domestic box office.

Update: The Avengers: Age of Ultron’s final domestic opening weekend tally came in at $191.3 million, $16.3 million lower than 2012’s The Avengers domestic opening weekend.

Marvel and other companies had predicted that The Avengers: Age of Ultron would see $210-230 million at its U.S. opening weekend, but the film has come in somewhat lower than expected, bringing in $187.6M during its opening weekend. We’re unsure what has caused the drop, but some reports suggest that the U.S. professional boxing match Saturday night may have caused attendance to be lower.

The Avengers took in $207.4 million during its domestic opening weekend at the box office back in 2012, so it still easily holds the #1 spot for biggest domestic opening weekend by around $20 million. It’s hard to know exactly why the second Avengers’ film didn’t take in the same or higher numbers in the U.S., but it’s still a massive financial success for Marvel and Disney, just not quite as big as everyone figured it would be.

Related: Read Hypable’s official review of The Avengers: Age of Ultron

Could fans be getting a little superhero fatigue? The movie certainly hasn’t garnered the same critical acclaim that The Avengers received, with Age of Ultron coming in at 75% on Rotten Tomatoes, while the first film currently holds a 92%. We’ll be curious to see how Marvel responds to this, as it’s still a massive box office success, but we imagine their hope was for it to beat the first film’s numbers.

The Avengers’ final domestic total was $623.3 million, with a worldwide total of $1.51 billion. Age of Ultron is currently at $187.6 million domestic, and $626.7 million worldwide. It’s still possible for Age of Ultron to surpass the first film, but unlikely now that the U.S. numbers are lower than expected. It’s actually the first Marvel sequel to open with lower numbers than its predecessor.

Age of Ultron was definitely a change of pace from the first movie, but we think it set up the next Marvel movies fairly well, with loads of new and exciting characters being added. Fans seemed to respond very well to Scarlet Witch and The Vision, and we know that Elizabeth Olsen is already filming Scarlet Witch scenes for Captain America: Civil War.

The Avengers: Age of Ultron set into motion the storylines for Captain America: Civil War, as well as the two-part sequel Infinity War. We’ll be sure to keep you updated as the final numbers continue to come in.

Why do you think ‘Age of Ultron’ pulled in lower numbers than ‘The Avengers’?