Spotify, the UK's biggest music streaming service, has started testing a way of filtering out songs which have explicit lyrics.
The feature has been introduced on its iPhone and iPad apps - six years after being requested on its online forums.
But some users have told BBC Radio 5 live: that the feature does not have enough controls.
Rivals such as Apple Music already have password-protected parental controls to skip explicit tracks.
Since 2011, streaming music providers have been expected to display the word "explicit" next to tracks that record companies believe are unsuitable for children.
Currently more than a third of the Top 50 songs in Spotify's UK chart contain explicit lyrics.
Mother Nicola Ford set up an online petition calling for the filter after she was caught out listening at home.
She said: "I'd had quite a few awkward moments, where the kids had been listening to songs on the radio, and suddenly our home filled with swear words when they played the same songs on Spotify.
"I set up a petition online and found that lots of people were petitioning for the same thing, so I got a lot of interest."
The new setting, which was first introduced at the start of April, greys out explicit songs and prevents them from playing, but it doesn't replace them with clean versions.
Nicola says this does not go far enough.
"The kids want to listen to the song that they've heard, so they will try and sneak the song in.
"If they are going to try to listen to the song, I'd like them to get the clean versions."
Others have complained that the setting. which is only available to Premium users, does not have a Pin code and can be changed by anyone with access to the device.
"It would be useful for the account holder, the parent, to control the setting," says Nicola.
"All these companies need to try really hard to help us manage what goes on in our homes, Spotify included. I think they could have shown interest a lot earlier."
Spotify describes the explicit content filter as a "beta version" and says it is currently being tested for "some users".
In a statement it said: "We are always testing new products and experiences at Spotify, but have no further news to share on a product launch at this time."