Motherwell manager Stuart McCall last week lambasted the "crazy" and little-known rule which prevented a club loaning more than one player to another SPFL club.
The SPFL board, at its meeting on Monday, decided that clubs can now lend up to two players to teams in a different division, although loans to teams in the same division are still restricted to one player.
SPFL chief executive Neil Doncaster said: "Member clubs had asked us to look at this rule which we acted on immediately and I'm very grateful to the SPFL board for responding so quickly and effectively.
"By making this rule adjustment while the transfer window is open it allows our clubs to consider all options open to them and plan accordingly."
McCall was speaking after trying to offload Adam Cummins and another player to Dundee for the rest of the season. While Cummins went to Dens Park, striker Bob McHugh has now completed a switch to Queen of the South.