During the last 155 years, the lighthouse had encountered changes from time to time.
- On March 15 1858, for the first time the light shines on the Gulf. It is a white and fixed light. The first sound signal is a nine pounds gauge fog canon.
- In 1861, the tower received a coating of stucco on the fire bricks facing.
- In 1869, the whale or porpoise oil burners are replaced by five big mammoth burners with flat wick to use refined white oil.
- In 1881 or 1882, the tower is wainscoted.
- In 1882, the decision to replace the fog canon is taken by the Department of Marine and Fisheries. A steam whistle begins to operate on August 15 1883.
- In 1884-1885, a fog horn replaces the steam whistle used as a backup in case of a horn failure.
- In 1892 or 1893, the stairs, floors and wainscotings are renewed.
- In 1894 or 1895, a well to supply water to the station is dug. The pump can provide up to ten gallons per minute.
- On November 1 1899, the steam whistle is primary used and the fog horn is used as a backup..
- In 1897 or 1898, new wainscoting and repair of the foundations.
- In 1903, official change from the white fixed light to a white light with occultation (flash 15 s, occultation 5 s). The replacement of the traditional lamps by one big oil steam burner with an incandescent wick. This change is very much welcomed by navigators.
- In 1906, the steam whistle is replaced by a diaphone, a pneumatic apparatus
- In 1916, the name of Cap-des-Rosiers for the cape and the name of the lighthouse station, is now used by the Canadian Geographic Council in replacement of the toponym of “Cape Rosier or Rozier” used earlier on the maps of the Admiralty and other English publications.
- In 1921 or1922, an oil steam burner with an incandescent wick of 55 mm is installed.
- In 1922 or 1923, it is proposed to change the lantern, but only a few repairs are done.
- In 1929 or 1930, some repairs are done on the tower.
- In 1950, the lighthouse station of Cap-des-Rosiers is electrified. A big 1000 watt light bulb takes place in the lantern. The oil steam burner is kept as a back up during the black-outs.
- On July 1954, a contract is granted to the company J.P.A. Normand Inc. to rebuild the outside facing of bricks which was in very bad state for a cost of $14,500.
- On February 1956, a contract is granted to the contractor Armand Joncas for the demolition of the keeper's old residence next to the tower as well as other old buildings, including the elimination of the signal mast, and for the construction of new buildings for the diaphone, the radio beacon and a stable). Cost of the contract: $14,000.
- On June 27, 1957, a fire is triggered by defects in the diaphone motors. The diaphone and radio beacon buildings recently built are destroyed.
- On December 27, 1957, a contract is granted to the Matane company Lanthier, Lafontaine and Manger Inc. to rebuild these buildings. Cost of the contract: $7,900.
- On August 1970, a 400 watt mercury steam electric lamp with a bigger luminous intensity and a longer life span is installed.
- In 1972, the lighthouse is partially automated.
- On June 11, 1973, the lighthouse station is designated National Historic Place of Canada by the Historic Sites and Monuments board of Canada.
- In 1981, the keeper’s house built in 1956 is demolished and the lighthouse automation is now completed and monitored.
- In 1984, the tower facing is renewed. The bricks are replaced by white marble stones.
- In 1993, some repairs are done to the facing.
- On March 31, 1994, the lighthouse is designated classified federal heritage building due to its historic importance and its architectural and environmental value.
- In 2000, spotlights installed around the structure of the lighttower to illuminate and emphasize it at night.
Repairs to the roofing and complete renovation of the inside of the reception house.
Interpretation panels installed to inform tourists about the lighthouse.
Repairs to the powder magazine.
Renovation to the comfort station.
Installation of an information kiosk close to the fence.Fences of wood replace those of metal.
Installation of a panoramic viewpoint with binoculars.
Trash cans and picnic tables installed.
Total cost of installation: $145,400.
- In 2008, the site is decontaminated.
- In 2008, the Cap-des-Rosiers lighthouse celebrates its 150th birthday.