Thai lawmakers have rejected a proposal, which could've opened a discussion on the king's role including curbing his power in politics.
The motion was one of seven items on an agenda for constitutional change, proposed by the civic rights group iLaw on behalf of protesters.
Parliament adopted only two proposals that would rewrite the country's military-composed charter,.. but still wouldn't affect the monarchy.
"The seventh amendment proposal has 212 votes - 209 votes were from the members of parliament, three from the senators. The votes did not reach the 366 (required) threshold."
It was not a surprise result, given that the majority of parliament supports the prime minister.
The entire upper house Senate was appointed by the former junta leader who came to power in a 2014 coup.
Wednesday's vote, which was in favor of amending the constitution, was not all good news for protesters whose voices were only partially heard.
Since July, student-led demonstrators have been calling for the removal of the prime minister, constitutional reform, and curbs on the powerful monarchy, to achieve greater democracy.
And thousands of people again took to the streets in Bangkok on the day of the announcement.
They returned bringing back their giant pool duck mascots, after witnessing police firing tear gas and water cannons which hurt dozens of their fellow demonstrators the day before.
"If the police hadn't fired the water cannon at us, we wouldn't have had to use them as a shield. It would be just a toy for kids."
The months-long protest is an unprecedented challenge against the highly monarchical society of Thailand, which can punish criticism against kingdom with up to 15 years in prison.
Lee Kyung-eun, Arirang News.