diff --git a/library/include/modules/Units.h b/library/include/modules/Units.h
index 0bfa47dce..e7e17b6a0 100644
--- a/library/include/modules/Units.h
+++ b/library/include/modules/Units.h
@@ -255,7 +255,6 @@ DFHACK_EXPORT bool isEggLayer(df::unit* unit);
 DFHACK_EXPORT bool isGrazer(df::unit* unit);
 DFHACK_EXPORT bool isMilkable(df::unit* unit);
 DFHACK_EXPORT bool isTrainableWar(df::unit* unit);
-DFHACK_EXPORT bool isMilkable(df::unit* unit);
 DFHACK_EXPORT bool isTrainableHunting(df::unit* unit);
 DFHACK_EXPORT bool isTamable(df::unit* unit);
 DFHACK_EXPORT bool isMale(df::unit* unit);