diff --git a/library/include/modules/Buildings.h b/library/include/modules/Buildings.h
index cb9091861..66745abe6 100644
--- a/library/include/modules/Buildings.h
+++ b/library/include/modules/Buildings.h
@@ -275,7 +275,6 @@ DFHACK_EXPORT bool isActivityZone(df::building * building);
 DFHACK_EXPORT bool isPenPasture(df::building * building);
 DFHACK_EXPORT bool isPitPond(df::building * building);
 DFHACK_EXPORT bool isActive(df::building * building);
-DFHACK_EXPORT bool isHospital(df::building * building);
 DFHACK_EXPORT bool isAnimalTraining(df::building * building);
 
 DFHACK_EXPORT df::building* findPenPitAt(df::coord coord);
diff --git a/library/modules/Buildings.cpp b/library/modules/Buildings.cpp
index 828768a54..389113483 100644
--- a/library/modules/Buildings.cpp
+++ b/library/modules/Buildings.cpp
@@ -1589,45 +1589,31 @@ bool Buildings::isPenPasture(df::building * building)
     if (!isActivityZone(building))
         return false;
 
-/* TODO: understand how this changes for v50
-    return ((df::building_civzonest*) building)->zone_flags.bits.pen_pasture != 0;
-*/ return false;
+    return ((df::building_civzonest*)building)->type == civzone_type::Pen;
 }
 
 bool Buildings::isPitPond(df::building * building)
 {
     if (!isActivityZone(building))
         return false;
-/* TODO: understand how this changes for v50
-    return ((df::building_civzonest*) building)->zone_flags.bits.pit_pond != 0;
-*/ return false;
+
+    return ((df::building_civzonest*)building)->type == civzone_type::Pond;
 }
 
 bool Buildings::isActive(df::building * building)
 {
     if (!isActivityZone(building))
         return false;
-/* TODO: understand how this changes for v50
-    return ((df::building_civzonest*) building)->zone_flags.bits.active != 0;
-*/ return false;
+    // 8 is the value obtained by reverse engineering
+    return ((df::building_civzonest*)building)->is_active == 8;
 }
 
-bool Buildings::isHospital(df::building * building)
- {
-     if (!isActivityZone(building))
-         return false;
-/* TODO: understand how this changes for v50
-     return ((df::building_civzonest*) building)->zone_flags.bits.hospital != 0;
-*/ return false;
- }
-
  bool Buildings::isAnimalTraining(df::building * building)
  {
      if (!isActivityZone(building))
          return false;
-/* TODO: understand how this changes for v50
-     return ((df::building_civzonest*) building)->zone_flags.bits.animal_training != 0;
-*/ return false;
+
+     return ((df::building_civzonest*)building)->type == civzone_type::AnimalTraining;
  }
 
 // returns building of pen/pit at cursor position (NULL if nothing found)
diff --git a/plugins/CMakeLists.txt b/plugins/CMakeLists.txt
index 3389303fd..df49c3d59 100644
--- a/plugins/CMakeLists.txt
+++ b/plugins/CMakeLists.txt
@@ -84,7 +84,7 @@ dfhack_plugin(autofarm autofarm.cpp)
 add_subdirectory(autolabor)
 #dfhack_plugin(automaterial automaterial.cpp LINK_LIBRARIES lua)
 dfhack_plugin(automelt automelt.cpp LINK_LIBRARIES lua)
-#dfhack_plugin(autonestbox autonestbox.cpp LINK_LIBRARIES lua)
+dfhack_plugin(autonestbox autonestbox.cpp LINK_LIBRARIES lua)
 #dfhack_plugin(autotrade autotrade.cpp)
 dfhack_plugin(blueprint blueprint.cpp LINK_LIBRARIES lua)
 #dfhack_plugin(burrows burrows.cpp LINK_LIBRARIES lua)