Solaris 8 make error building man pages

The makefile in the man directory uses GNU "simply expanded variables" with
these lines:

MAN1 := $(MAN1SRC:.=.$(manext1))
MAN5 := $(MAN5SRC:.=.$(manext5))
MAN8 := $(MAN8SRC:.=.$(manext8))

However, Solaris 8 uses a System V make that uses ':=' for conditional
macro assignment. 

My reading of the make file (and testing) indicates that we can change
":=" to "=" without a problem, so the lines would be 

MAN1 = $(MAN1SRC:.=.$(manext1))
MAN5 = $(MAN5SRC:.=.$(manext5))
MAN8 = $(MAN8SRC:.=.$(manext8))

Is this right?