diff --git a/doc/en/dia.1 b/doc/en/dia.1
index fd4a8fb..d3db34f 100644
--- a/doc/en/dia.1
+++ b/doc/en/dia.1
@@ -130,6 +130,10 @@ mp
 (TeX MetaPost macros)
 .TP 3n
 \(bu
+pdf
+(Portable Document Format)
+.TP 3n
+\(bu
 plt
 or
 hpgl
diff --git a/doc/eu/dia.1 b/doc/eu/dia.1
index fd4a8fb..d3db34f 100644
--- a/doc/eu/dia.1
+++ b/doc/eu/dia.1
@@ -130,6 +130,10 @@ mp
 (TeX MetaPost macros)
 .TP 3n
 \(bu
+pdf
+(Portable Document Format)
+.TP 3n
+\(bu
 plt
 or
 hpgl

