Production of the M4 stopped briefly in 1972. Its successor, the M5 had been introduced in 1971. However, the relatively bulky and expensive M5 met with a cool reception, and sales did not live up to Leica's expectations. Production of the M4 was therefore restarted quickly until 1975. In the year 1975, a special edition was made for Leica's 50th Anniversary, and in 1977 the company launched the updated M4-2, which was based on the M4's body, but with a streamlined production process that reduced manufacturing cost. The M4-2 added a hot shoe and motor drive compatibility as standard, but removed the self-timer.