diff --git a/Include/Library.nsh b/Include/Library.nsh
index b135d798..dce323d4 100644
--- a/Include/Library.nsh
+++ b/Include/Library.nsh
@@ -571,7 +571,7 @@ Example:
 
     !endif
 
-    !ifdef INSTALLLIB_LIBTYPE_TLB | UNINSTALLLIB_LIBTYPE_REGDLLTLB
+    !ifdef UNINSTALLLIB_LIBTYPE_TLB | UNINSTALLLIB_LIBTYPE_REGDLLTLB
 
       TypeLib::UnRegister $R1