diff --git a/src/Kaleidoscope-HostOS.h b/src/Kaleidoscope-HostOS.h
index 3c0126a1..f3295a91 100644
--- a/src/Kaleidoscope-HostOS.h
+++ b/src/Kaleidoscope-HostOS.h
@@ -20,5 +20,3 @@
 
 #include <Kaleidoscope/HostOS-Base.h>
 #include <Kaleidoscope/HostOS-Guesser.h>
-
-extern KaleidoscopePlugins::HostOS::Base HostOS;
diff --git a/src/Kaleidoscope/HostOS-Base.h b/src/Kaleidoscope/HostOS-Base.h
index 20de6012..6ef48216 100644
--- a/src/Kaleidoscope/HostOS-Base.h
+++ b/src/Kaleidoscope/HostOS-Base.h
@@ -48,3 +48,5 @@ namespace KaleidoscopePlugins {
     };
   };
 };
+
+extern KaleidoscopePlugins::HostOS::Base HostOS;