diff --git a/mk/tools/replace.mk b/mk/tools/replace.mk
index b7feb77..26b7f02 100644
--- a/mk/tools/replace.mk
+++ b/mk/tools/replace.mk
@@ -187,7 +187,8 @@ _TOOLS_DEPMETHOD.gsoelim=	${_TOOLS_DEPMETHOD.soelim}
 # otherwise if this is a particular ${MACHINE_PLATFORM} listed above.
 #
 .for _t_ in ${_USE_TOOLS}
-.  if defined(TOOLS_PLATFORM.${_t_}) && !empty(TOOLS_PLATFORM.${_t_})
+.  if defined(TOOLS_PLATFORM.${_t_}) && !empty(TOOLS_PLATFORM.${_t_}) && \
+	empty(PREFER_PKGSRC:M[yY][eE][sS]) && empty(PREFER_PKGSRC:M${_t_})
 _TOOLS_USE_PKGSRC.${_t_}?=	no
 .  endif
 _TOOLS_USE_PKGSRC.${_t_}?=	yes