diff --git a/src/GUI/Highlight.cxx b/src/GUI/Highlight.cxx
index 5512acab6..fac356184 100644
--- a/src/GUI/Highlight.cxx
+++ b/src/GUI/Highlight.cxx
@@ -668,3 +668,7 @@ void Highlight::addPropertyProperty(const std::string& from0, const std::string&
         }
     }
 }
+
+// Register the subsystem.
+SGSubsystemMgr::Registrant<Highlight> registrantHighlight(
+    SGSubsystemMgr::INIT);
diff --git a/src/Main/ErrorReporter.cxx b/src/Main/ErrorReporter.cxx
index da9171a32..af7ec44a9 100644
--- a/src/Main/ErrorReporter.cxx
+++ b/src/Main/ErrorReporter.cxx
@@ -942,3 +942,7 @@ std::string ErrorReporter::threadSpecificContextValue(const std::string& key)
 
 
 } // namespace flightgear
+
+// Register the subsystem.
+SGSubsystemMgr::Registrant<flightgear::ErrorReporter> registrantErrorReporter(
+    SGSubsystemMgr::GENERAL);
diff --git a/src/Viewer/GraphicsPresets.cxx b/src/Viewer/GraphicsPresets.cxx
index e47d8e35d..bb08415d5 100644
--- a/src/Viewer/GraphicsPresets.cxx
+++ b/src/Viewer/GraphicsPresets.cxx
@@ -547,4 +547,9 @@ bool GraphicsPresets::saveToXML(const SGPath& path, const std::string& name, con
     return true;
 }
 
+// Register the subsystem.
+SGSubsystemMgr::Registrant<GraphicsPresets> registrantGraphicsPresets(
+    SGSubsystemMgr::DISPLAY);
+
+
 } // namespace flightgear