diff --git a/simgear/scene/tsync/terrasync.cxx b/simgear/scene/tsync/terrasync.cxx
index 69e381f2..a1715097 100644
--- a/simgear/scene/tsync/terrasync.cxx
+++ b/simgear/scene/tsync/terrasync.cxx
@@ -1115,3 +1115,9 @@ void SGTerraSync::reposition()
 {
     // stub, remove
 }
+
+
+// Register the subsystem.
+SGSubsystemMgr::Registrant<SGTerraSync> registrantSGTerraSync(
+    SGSubsystemMgr::GENERAL,
+    {{"FGRenderer", SGSubsystemMgr::Dependency::NONSUBSYSTEM_HARD}});
diff --git a/simgear/structure/SGPerfMon.cxx b/simgear/structure/SGPerfMon.cxx
index c4d7caed..da754cab 100644
--- a/simgear/structure/SGPerfMon.cxx
+++ b/simgear/structure/SGPerfMon.cxx
@@ -138,3 +138,7 @@ SGPerformanceMonitor::reportTiming(const string& name, SampleStatistic* timeStat
 
     timeStat->reset();
 }
+
+
+// Register the subsystem.
+//SGSubsystemMgr::Registrant<SGPerformanceMonitor> registrantSGPerformanceMonitor;
diff --git a/simgear/structure/event_mgr.cxx b/simgear/structure/event_mgr.cxx
index 9d0e0ae0..2160d6c3 100644
--- a/simgear/structure/event_mgr.cxx
+++ b/simgear/structure/event_mgr.cxx
@@ -126,6 +126,11 @@ void SGEventMgr::dump()
     _rtQueue.dump();
 }
 
+// Register the subsystem.
+SGSubsystemMgr::Registrant<SGEventMgr> registrantSGEventMgr(
+    SGSubsystemMgr::DISPLAY);
+
+
 ////////////////////////////////////////////////////////////////////////
 // SGTimerQueue
 // This is the priority queue implementation: