diff --git a/src/monster.cpp b/src/monster.cpp
index 653a337f1d29e..794024768f800 100644
--- a/src/monster.cpp
+++ b/src/monster.cpp
@@ -2547,6 +2547,11 @@ units::mass monster::get_weight() const
     return units::operator*( type->weight, get_size() / type->size );
 }
 
+units::mass monster::weight_capacity() const
+{
+    return type->weight * type->mountable_weight_ratio;
+}
+
 units::volume monster::get_volume() const
 {
     return units::operator*( type->volume, get_size() / type->size );
diff --git a/src/monster.h b/src/monster.h
index 43e456a1060b7..266b0a29ede6a 100644
--- a/src/monster.h
+++ b/src/monster.h
@@ -107,6 +107,7 @@ class monster : public Creature
         void spawn( const tripoint &p );
         m_size get_size() const override;
         units::mass get_weight() const override;
+        units::mass weight_capacity() const override;
         units::volume get_volume() const;
         int get_hp( hp_part ) const override;
         int get_hp() const override;