diff --git a/tex/latex/biblatex/biblatex1.sty b/tex/latex/biblatex/biblatex1.sty
index 6a51f2872..521b50dfc 100644
--- a/tex/latex/biblatex/biblatex1.sty
+++ b/tex/latex/biblatex/biblatex1.sty
@@ -4576,6 +4576,7 @@
   \do{langgerman}%
   \do{langgreek}%
   \do{langitalian}%
+  \do{langjapanese}%
   \do{langlatin}%
   \do{langnorwegian}%
   \do{langpolish}%
diff --git a/tex/latex/biblatex/biblatex2.sty b/tex/latex/biblatex/biblatex2.sty
index 09479b1a3..87c100a2b 100644
--- a/tex/latex/biblatex/biblatex2.sty
+++ b/tex/latex/biblatex/biblatex2.sty
@@ -4338,6 +4338,7 @@
   \do{langgerman}%
   \do{langgreek}%
   \do{langitalian}%
+  \do{langjapanese}%
   \do{langlatin}%
   \do{langnorwegian}%
   \do{langpolish}%