diff --git a/lib/src/bulgarian/DiffBul.gf b/lib/src/bulgarian/DiffBul.gf
deleted file mode 100644
index 55cf8c963..000000000
--- a/lib/src/bulgarian/DiffBul.gf
+++ /dev/null
@@ -1,21 +0,0 @@
-instance DiffBul of DiffSlavic = open CommonSlavic, Prelude in {
-
-  param
-    Case  = Acc | Dat ;
-
-    Species = Indef | Def ;
-
-    NForm = 
-        NF Number Species
-      | NFSgDefNom
-      | NFPlCount
-      | NFVocative
-      ;
-
-  oper
-    Agr = {gn : GenNum ; p : Person} ;
-
-    agrP3 : GenNum -> Agr = \gn -> 
-      {gn = gn; p = P3} ;
-
-}
\ No newline at end of file