diff --git a/code/IO.f90 b/code/IO.f90
index 22b56d819..f5db5c1f1 100644
--- a/code/IO.f90
+++ b/code/IO.f90
@@ -142,7 +142,7 @@ recursive function IO_read(fileUnit,reset) result(line)
    pathOn(stack) = path(1:scan(path,SEP,.true.))//input                                             ! glue include to current file's dir
  endif
 
- open(newunit=unitOn(stack),iostat=myStat,file=pathOn(stack),action=read)                           ! open included file
+ open(newunit=unitOn(stack),iostat=myStat,file=pathOn(stack),action='read')                         ! open included file
  if (myStat /= 0_pInt) call IO_error(100_pInt,el=myStat,ext_msg=pathOn(stack))
 
  line = IO_read(fileUnit)