diff --git a/src/mapgen.cpp b/src/mapgen.cpp
index 880ea1ee..ceaabbb1 100644
--- a/src/mapgen.cpp
+++ b/src/mapgen.cpp
@@ -20,6 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mapgen.h"
 #include "voxel.h"
 #include "noise.h"
+#include "gamedef.h"
 #include "mg_biome.h"
 #include "mapblock.h"
 #include "mapnode.h"
@@ -381,6 +382,12 @@ void GenerateNotifier::getEvents(
 ///////////////////////////////////////////////////////////////////////////////
 
 
+GenElementManager::GenElementManager(IGameDef *gamedef)
+{
+	m_resolver = gamedef->getNodeDefManager()->getResolver();
+}
+
+
 GenElementManager::~GenElementManager()
 {
 	for (size_t i = 0; i != m_elements.size(); i++)
diff --git a/src/mapgen.h b/src/mapgen.h
index b4cfd67b..03850cd1 100644
--- a/src/mapgen.h
+++ b/src/mapgen.h
@@ -178,7 +178,7 @@ class GenElementManager {
 	static const char *ELEMENT_TITLE;
 	static const size_t ELEMENT_LIMIT = -1;
 
-	GenElementManager() {}
+	GenElementManager(IGameDef *gamedef);
 	virtual ~GenElementManager();
 
 	virtual GenElement *create(int type) = 0;
@@ -192,6 +192,7 @@ class GenElementManager {
 	virtual GenElement *getByName(const std::string &name);
 
 protected:
+	NodeResolver *m_resolver;
 	std::vector<GenElement *> m_elements;
 };
 
diff --git a/src/mg_biome.cpp b/src/mg_biome.cpp
index 13dc67e7..96fe443a 100644
--- a/src/mg_biome.cpp
+++ b/src/mg_biome.cpp
@@ -32,10 +32,9 @@ const char *BiomeManager::ELEMENT_TITLE = "biome";
 
 ///////////////////////////////////////////////////////////////////////////////
 
-BiomeManager::BiomeManager(IGameDef *gamedef)
+BiomeManager::BiomeManager(IGameDef *gamedef) :
+	GenElementManager(gamedef)
 {
-	m_resolver  = gamedef->getNodeDefManager()->getResolver();
-
 	// Create default biome to be used in case none exist
 	Biome *b = new Biome;
 
diff --git a/src/mg_biome.h b/src/mg_biome.h
index 04567267..f1539dac 100644
--- a/src/mg_biome.h
+++ b/src/mg_biome.h
@@ -71,9 +71,6 @@ class BiomeManager : public GenElementManager {
 	void calcBiomes(s16 sx, s16 sy, float *heat_map, float *humidity_map,
 		s16 *height_map, u8 *biomeid_map);
 	Biome *getBiome(float heat, float humidity, s16 y);
-
-private:
-	NodeResolver *m_resolver;
 };
 
 #endif
diff --git a/src/mg_decoration.cpp b/src/mg_decoration.cpp
index 20b9fbda..14368c09 100644
--- a/src/mg_decoration.cpp
+++ b/src/mg_decoration.cpp
@@ -38,6 +38,12 @@ FlagDesc flagdesc_deco[] = {
 ///////////////////////////////////////////////////////////////////////////////
 
 
+DecorationManager::DecorationManager(IGameDef *gamedef) :
+	GenElementManager(gamedef)
+{
+}
+
+
 size_t DecorationManager::placeAllDecos(Mapgen *mg, u32 seed, v3s16 nmin, v3s16 nmax)
 {
 	size_t nplaced = 0;
@@ -55,6 +61,19 @@ size_t DecorationManager::placeAllDecos(Mapgen *mg, u32 seed, v3s16 nmin, v3s16
 }
 
 
+void DecorationManager::clear()
+{
+	for (size_t i = 0; i < m_elements.size(); i++) {
+		Decoration *deco = (Decoration *)m_elements[i];
+		if (!deco)
+			continue;
+
+		deco->dropResolverEntries(m_resolver);
+	}
+	m_elements.clear();
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 
 
@@ -291,6 +310,13 @@ int DecoSimple::getHeight()
 }
 
 
+void DecoSimple::dropResolverEntries(NodeResolver *resolver)
+{
+	resolver->cancelNodeList(&c_decos);
+	resolver->cancelNodeList(&c_spawnby);
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 
 
diff --git a/src/mg_decoration.h b/src/mg_decoration.h
index f360e3b7..dffb524f 100644
--- a/src/mg_decoration.h
+++ b/src/mg_decoration.h
@@ -81,6 +81,7 @@ class Decoration : public GenElement {
 
 	virtual size_t generate(Mapgen *mg, PseudoRandom *pr, s16 max_y, v3s16 p) = 0;
 	virtual int getHeight() = 0;
+	virtual void dropResolverEntries(NodeResolver *resolver) {}
 };
 
 class DecoSimple : public Decoration {
@@ -96,6 +97,7 @@ class DecoSimple : public Decoration {
 	bool canPlaceDecoration(ManualMapVoxelManipulator *vm, v3s16 p);
 	virtual size_t generate(Mapgen *mg, PseudoRandom *pr, s16 max_y, v3s16 p);
 	virtual int getHeight();
+	virtual void dropResolverEntries(NodeResolver *resolver);
 };
 
 class DecoSchematic : public Decoration {
@@ -123,7 +125,7 @@ class DecorationManager : public GenElementManager {
 	static const char *ELEMENT_TITLE;
 	static const size_t ELEMENT_LIMIT = 0x10000;
 
-	DecorationManager(IGameDef *gamedef) {}
+	DecorationManager(IGameDef *gamedef);
 	~DecorationManager() {}
 
 	Decoration *create(int type)
@@ -140,6 +142,8 @@ class DecorationManager : public GenElementManager {
 		}
 	}
 
+	void clear();
+
 	size_t placeAllDecos(Mapgen *mg, u32 seed, v3s16 nmin, v3s16 nmax);
 };
 
diff --git a/src/mg_ore.cpp b/src/mg_ore.cpp
index d94b861c..de3f6b0e 100644
--- a/src/mg_ore.cpp
+++ b/src/mg_ore.cpp
@@ -37,6 +37,12 @@ FlagDesc flagdesc_ore[] = {
 ///////////////////////////////////////////////////////////////////////////////
 
 
+OreManager::OreManager(IGameDef *gamedef) :
+	GenElementManager(gamedef)
+{
+}
+
+
 size_t OreManager::placeAllOres(Mapgen *mg, u32 seed, v3s16 nmin, v3s16 nmax)
 {
 	size_t nplaced = 0;
@@ -54,6 +60,20 @@ size_t OreManager::placeAllOres(Mapgen *mg, u32 seed, v3s16 nmin, v3s16 nmax)
 }
 
 
+void OreManager::clear()
+{
+	for (size_t i = 0; i < m_elements.size(); i++) {
+		Ore *ore = (Ore *)m_elements[i];
+		if (!ore)
+			continue;
+
+		m_resolver->cancelNodeList(&ore->c_wherein);
+		m_resolver->cancelNode(&ore->c_ore);
+	}
+	m_elements.clear();
+}
+
+
 ///////////////////////////////////////////////////////////////////////////////
 
 
@@ -169,4 +189,3 @@ void OreSheet::generate(ManualMapVoxelManipulator *vm, int seed,
 		}
 	}
 }
-
diff --git a/src/mg_ore.h b/src/mg_ore.h
index b6db860b..585d58f3 100644
--- a/src/mg_ore.h
+++ b/src/mg_ore.h
@@ -99,7 +99,7 @@ class OreManager : public GenElementManager {
 	static const char *ELEMENT_TITLE;
 	static const size_t ELEMENT_LIMIT = 0x10000;
 
-	OreManager(IGameDef *gamedef) {}
+	OreManager(IGameDef *gamedef);
 	~OreManager() {}
 
 	Ore *create(int type)
@@ -116,6 +116,8 @@ class OreManager : public GenElementManager {
 		}
 	}
 
+	void clear();
+
 	size_t placeAllOres(Mapgen *mg, u32 seed, v3s16 nmin, v3s16 nmax);
 };
 
diff --git a/src/mg_schematic.cpp b/src/mg_schematic.cpp
index bb60cf5f..a7882464 100644
--- a/src/mg_schematic.cpp
+++ b/src/mg_schematic.cpp
@@ -30,6 +30,14 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 const char *SchematicManager::ELEMENT_TITLE = "schematic";
 
+///////////////////////////////////////////////////////////////////////////////
+
+
+SchematicManager::SchematicManager(IGameDef *gamedef) :
+	GenElementManager(gamedef)
+{
+}
+
 
 ///////////////////////////////////////////////////////////////////////////////
 
diff --git a/src/mg_schematic.h b/src/mg_schematic.h
index 9d4d4a71..df54d79b 100644
--- a/src/mg_schematic.h
+++ b/src/mg_schematic.h
@@ -76,7 +76,7 @@ class SchematicManager : public GenElementManager {
 	static const char *ELEMENT_TITLE;
 	static const size_t ELEMENT_LIMIT = 0x10000;
 
-	SchematicManager(IGameDef *gamedef) {}
+	SchematicManager(IGameDef *gamedef);
 	~SchematicManager() {}
 
 	Schematic *create(int type)
diff --git a/src/script/lua_api/l_mapgen.cpp b/src/script/lua_api/l_mapgen.cpp
index 3fe6fb99..177e0d85 100644
--- a/src/script/lua_api/l_mapgen.cpp
+++ b/src/script/lua_api/l_mapgen.cpp
@@ -464,6 +464,20 @@ int ModApiMapgen::l_clear_registered_biomes(lua_State *L)
 	return 0;
 }
 
+int ModApiMapgen::l_clear_registered_decorations(lua_State *L)
+{
+	DecorationManager *dmgr = getServer(L)->getEmergeManager()->decomgr;
+	dmgr->clear();
+	return 0;
+}
+
+int ModApiMapgen::l_clear_registered_ores(lua_State *L)
+{
+	OreManager *omgr = getServer(L)->getEmergeManager()->oremgr;
+	omgr->clear();
+	return 0;
+}
+
 // register_decoration({lots of stuff})
 int ModApiMapgen::l_register_decoration(lua_State *L)
 {
@@ -789,7 +803,10 @@ void ModApiMapgen::Initialize(lua_State *L, int top)
 	API_FCT(register_biome);
 	API_FCT(register_decoration);
 	API_FCT(register_ore);
+
 	API_FCT(clear_registered_biomes);
+	API_FCT(clear_registered_decorations);
+	API_FCT(clear_registered_ores);
 
 	API_FCT(create_schematic);
 	API_FCT(place_schematic);
diff --git a/src/script/lua_api/l_mapgen.h b/src/script/lua_api/l_mapgen.h
index 76f60a2d..87ae9fd8 100644
--- a/src/script/lua_api/l_mapgen.h
+++ b/src/script/lua_api/l_mapgen.h
@@ -55,6 +55,12 @@ class ModApiMapgen : public ModApiBase {
 	// clear_registered_biomes()
 	static int l_clear_registered_biomes(lua_State *L);
 
+	// clear_registered_decorations()
+	static int l_clear_registered_decorations(lua_State *L);
+
+	// clear_registered_ores
+	static int l_clear_registered_ores(lua_State *L);
+
 	// create_schematic(p1, p2, probability_list, filename)
 	static int l_create_schematic(lua_State *L);