China’s booming box office and seemingly inexhaustible cash reserves have provided a much-needed boost to Hollywood as it faces slowing ticket sales in the United States and challenges from Amazon and Netflix.

But Hollywood’s embrace of China has not come without strings attached.

So when the creators of “Pixels” wanted to show aliens blasting a hole in the Great Wall of China, Sony executives worried that the scene might prevent the 2015 movie’s release in China, leaked studio emailsshow. They blew up the Taj Mahal instead.

In the 1960s, Marvel Comics introduced a mystical guru character known as the Ancient One into its universe. He was portrayed as an elderly Tibetan man.

But in the 2016 movie “Doctor Strange,” the Ancient One is Celtic, played by the white actress Tilda Swinton. Moviemakers decided to change the character’s ethnicity early in the process, reportedly to avoid offending the Chinese government.

As recently as two decades ago, major Hollywood movies were sharply critical of China. “Seven Years in Tibet,” which depicts Chinese soldiers brutalizing Tibetans, was one of the top 100 grossing movies of 1997. Also that year, Disney released Martin Scorsese’s “Kundun” — a sympathetic portrayal of the Dalai Lama’s early life in Mao-era China and his subsequent exile in India — despite objections from the Chinese authorities.

“You’re not going to see something that’s like ‘Seven Years in Tibet’ anymore,” said Larry Shinagawa, a professor at Hawaii Tokai International College who specializes in Asian and Asian-American studies. Studios that make films critical of China, he said, risk being banned from releasing movies in the country.

At stake for China is more than just the validation of Hollywood’s powerbrokers and celebrities. In speeches and at forums, President Xi Jinping has repeatedly emphasized the need to “tell China’s story well” — to make sure a coherent, compelling and, most important, Communist Party-sanctioned narrative of China’s rise to power reaches global audiences.

“There is a notion that its propaganda has not worked well enough,” said Orville Schell, the director of the Center on U.S.-China Relations at the Asia Society. “So this is where the film industry comes in. There’s a real sensitivity to the blockbuster power of Hollywood.”

China has raised its influence in Hollywood by bankrolling a growing number of top-tier films.