diff --git a/src/norwegian/DiffNor.gf b/src/norwegian/DiffNor.gf
index 41b16860a..0c807c6ac 100644
--- a/src/norwegian/DiffNor.gf
+++ b/src/norwegian/DiffNor.gf
@@ -16,7 +16,6 @@ instance DiffNor of DiffScand = open CommonScand, Prelude in {
     neutrum = NNeutr ;
 
     detDef : Species = Def ;
-    artDef : GenNum -> Str = \gn -> gennumForms "den" "det" "de" ! gn ;
 
     Verb : Type = {
       s : VForm => Str ;
diff --git a/src/nynorsk/DiffNno.gf b/src/nynorsk/DiffNno.gf
index 02a3b6409..5c6d6c916 100644
--- a/src/nynorsk/DiffNno.gf
+++ b/src/nynorsk/DiffNno.gf
@@ -16,7 +16,6 @@ instance DiffNno of DiffScand = open CommonScand, Prelude in {
     neutrum = NNeutr ;
 
     detDef : Species = Def ;
-    artDef : GenNum -> Str = \gn -> gennumForms "den" "det" "dei" ! gn ;
 
     Verb : Type = {
       s : VForm => Str ;