-\DeclareRobustCommand\romanseries[1]{\@forced@seriesfalse\merge@font@series{#1}}
-\DeclareRobustCommand\kanjiseries[1]{\@forced@seriesfalse\merge@kanji@series{#1}}
-\DeclareRobustCommand\fontseries[1]{%
- \@forced@seriesfalse\merge@font@series{#1}\merge@kanji@series{#1}}
-\DeclareRobustCommand\romanseriesforce[1]{\@forced@seriestrue\merge@font@series{#1}}
-\DeclareRobustCommand\kanjiseriesforce[1]{\@forced@seriestrue\merge@kanji@series{#1}}
-\DeclareRobustCommand\fontseriesforce[1]{%
- \@forced@seriestrue\merge@font@series{#1}\merge@kanji@series{#1}}
+\ifnum\ltj@@latex@plv=300 % pl3, 4
+ \DeclareRobustCommand\romanseries[1]{\merge@font@series{#1}}
+ \DeclareRobustCommand\kanjiseries[1]{\merge@kanji@series{#1}}
+ \DeclareRobustCommand\fontseries[1]{%
+ \merge@font@series{#1}\merge@kanji@series{#1}}
+ \DeclareRobustCommand\romanseriesforce[1]{\edef\f@series{#1}}
+ \DeclareRobustCommand\kanjiseriesforce[1]{\edef\k@series{#1}}
+ \DeclareRobustCommand\fontseriesforce[1]{%
+ \edef\f@series{#1}\edef\k@series{#1}}
+\else % pl 5
+ \DeclareRobustCommand\romanseries[1]{\@forced@seriesfalse\merge@font@series{#1}}
+ \DeclareRobustCommand\kanjiseries[1]{\@forced@seriesfalse\merge@kanji@series{#1}}
+ \DeclareRobustCommand\fontseries[1]{%
+ \@forced@seriesfalse\merge@font@series{#1}\merge@kanji@series{#1}}
+ \DeclareRobustCommand\romanseriesforce[1]{\@forced@seriestrue\merge@font@series{#1}}
+ \DeclareRobustCommand\kanjiseriesforce[1]{\@forced@seriestrue\merge@kanji@series{#1}}
+ \DeclareRobustCommand\fontseriesforce[1]{%
+ \@forced@seriestrue\merge@font@series{#1}\merge@kanji@series{#1}}
+\fi