Children's TV channel Boomerang is to edit scenes from Tom and Jerry cartoons where characters are shown smoking.
Tom and Jerry first appeared in 1940 cartoon Puss Gets the Boot
The move follows an investigation by media watchdog Ofcom into a viewer's complaint that the vintage animations were not appropriate for young viewers.
The watchdog recognised the "historic" cartoons were made at a time "when smoking was more generally accepted".
However, Boomerang will only edit those cartoons where smoking appears to be "condoned, acceptable or glamorised".
Two such cartoons include Texas Tom from 1950 and Tennis Chumps from 1949.
In the former Tom is shown trying to impress a female cat by rolling a cigarette, lighting it and smoking it with one hand. In the latter, Tom's tennis opponent is seen smoking a large cigar.
"We note that in Tom and Jerry smoking usually appears in a stylised manner," said Ofcom.
However, it said that "the level of editorial justification required for the inclusion of smoking in such cartoons is necessarily high".
"Depictions of smoking may not be problematic given the context," it continued.
"But broadcasters need to make a judgement about the extent to which a particular scene may or may not genuinely influence children."
Channel 4 has avoided censure after Sir Elton John swore on a live edition of Paul O'Grady's teatime show.
On the programme broadcast 9 May this year, the British singer said he had changed his name from Reginald Dwight because it had made him sound "like a banker, or a w****r".
Ten viewers contacted Ofcom complaining that the language was inappropriate for the time of broadcast.
The media watchdog said the use of the word was "unfortunate" but that it accepted C4 had taken steps to avoid similar occurrences in future.