diff --git a/code/ryzom/server/src/ai_service/commands.cpp b/code/ryzom/server/src/ai_service/commands.cpp
index d257d0492..7a4ff6f0d 100644
--- a/code/ryzom/server/src/ai_service/commands.cpp
+++ b/code/ryzom/server/src/ai_service/commands.cpp
@@ -577,10 +577,10 @@ NLMISC_COMMAND(createStaticAIInstance, "Create a new static AIInstance for a giv
 	CUsedContinent &uc = CUsedContinent::instance();
 
 	const	uint32 in = uc.getInstanceForContinent(args[0]);
-	if (in == ~0)
+	if (in == INVALID_AI_INSTANCE)
 	{
 		nlwarning("The continent '%s' is unknow or not active. Can't create instance, FATAL", args[0].c_str());
-		nlassert(in != ~0);
+		nlassert(in != INVALID_AI_INSTANCE);
 //		nlassertex(in != ~0, ("The continent '%s' is unknow or not active. Can't create instance, FATAL", args[0].c_str()));
 	}
 
diff --git a/code/ryzom/server/src/ai_share/primitive_parser.cpp b/code/ryzom/server/src/ai_share/primitive_parser.cpp
index 892120902..dd52b4d7a 100644
--- a/code/ryzom/server/src/ai_share/primitive_parser.cpp
+++ b/code/ryzom/server/src/ai_share/primitive_parser.cpp
@@ -4176,7 +4176,7 @@ NLMISC_COMMAND(loadMap,"load a complete set of primitive files","<map name>")
 		// check that the continent is active
 		CUsedContinent &uc = CUsedContinent::instance();
 		uint32 in = uc.getInstanceForContinent(continentName);
-		if (in == ~0)
+		if (in == INVALID_AI_INSTANCE)
 		{
 			log.displayNL("loadMap : while loading map '%s', can't load primitive '%s' coz continent '%s' is not active",
 				args[0].c_str(),
@@ -4216,7 +4216,7 @@ NLMISC_COMMAND(unloadMap,"unload a complete set of primitive files","<map name>"
 			// check that the continent is active
 			CUsedContinent &uc = CUsedContinent::instance();
 			uint32 in = uc.getInstanceForContinent(continentName);
-			if (in == ~0)
+			if (in == INVALID_AI_INSTANCE)
 			{
 				log.displayNL("unloadMap : while loading map '%s', can't load primitive '%s' coz continent '%s' is not active",
 					args[0].c_str(),
diff --git a/code/ryzom/server/src/entities_game_service/admin.cpp b/code/ryzom/server/src/entities_game_service/admin.cpp
index 20941e77f..6e06da000 100644
--- a/code/ryzom/server/src/entities_game_service/admin.cpp
+++ b/code/ryzom/server/src/entities_game_service/admin.cpp
@@ -420,7 +420,7 @@ bool getAIInstanceFromGroupName(string& groupName, uint32& instanceNumber)
 	{
 		string continent = groupName.substr(0, groupName.find('@'));
 		uint32 nr = CUsedContinent::instance().getInstanceForContinent(continent);
-		if (nr == ~0)
+		if (nr == INVALID_AI_INSTANCE)
 		{
 			return false;
 		}
diff --git a/code/ryzom/server/src/server_share/used_continent.cpp b/code/ryzom/server/src/server_share/used_continent.cpp
index 9e9a310d9..9d2b48f0d 100644
--- a/code/ryzom/server/src/server_share/used_continent.cpp
+++ b/code/ryzom/server/src/server_share/used_continent.cpp
@@ -106,7 +106,7 @@ uint32	CUsedContinent::getInstanceForContinent(const std::string &continentName)
 	if (it != _Continents.end())
 		return it->ContinentInstance;
 	else
-		return ~0;
+		return INVALID_AI_INSTANCE;
 }
 
 uint32	CUsedContinent::getInstanceForContinent(CONTINENT::TContinent continentEnum) const
@@ -116,7 +116,7 @@ uint32	CUsedContinent::getInstanceForContinent(CONTINENT::TContinent continentEn
 	if (it != _Continents.end())
 		return it->ContinentInstance;
 	else
-		return ~0;
+		return INVALID_AI_INSTANCE;
 }
 
 const std::string &CUsedContinent::getContinentForInstance(uint32 instanceNumber) const