The Philippine House of Representatives has approved a bill making enthusiastic singing of the national anthem compulsory.
"The singing shall be mandatory and must be done with fervour," the bill states. The word "mandatory" is not in the existing legislation.
It also provides official music for the tune, which must be adhered to.
Punishment for breaking the rules could include a fine of 50,000-100,000 pesos (£780-£1,560; $2,800-$5,590).
That fine is substantially more than the current minimum and maximum of 5,000-20,000 pesos (£78-£312).
Offenders will also be issued a warning before being publicly "named and shamed" in a national newspaper.
"Any act which casts contempt, dishonour or ridicule upon the national anthem shall be penalised," the bill says.
The bill makes a wide range of other stipulations, including that everyone must stand and salute when the first note of the song, Lupang Hinirang, is played - and requiring the school system to ensure every student memorises the words.
It has now been sent to the country's other house of parliament, the senate, for approval.
Commenting on an earlier version of the bill in April, one of its authors, Maximo Rodriguez Jr, said disrespecting the national anthem often happens in cinemas, where customers do not stand for the anthem.
"The national anthem embodies and expresses the aspirations, dreams, ideals, longings, commitment and determination, nationalism and patriotism, sentiment and spirit of the people," he said.
The same bill, known as the revised flag and heraldic code, contains many other rules about the display of the national flag and other emblems.
It includes several proposals from a 2010 draft to criminalise improper singing of the national anthem, including a strict requirement to keep the timing between 100 and 120 beats per minute.