diff --git a/tools/editworld/src/EditWorld.dsp b/tools/editworld/src/EditWorld.dsp
index 4ae9fa015..c551bdca3 100644
--- a/tools/editworld/src/EditWorld.dsp
+++ b/tools/editworld/src/EditWorld.dsp
@@ -374,7 +374,7 @@ SOURCE=.\macros.h
 # End Source File
 # Begin Source File
 
-SOURCE=.\nainfrm.h
+SOURCE=.\mainfrm.h
 # End Source File
 # Begin Source File