diff --git a/packages/windows/installer/NTMakefile b/packages/windows/installer/NTMakefile
index 9252cc1c9..bd87a0e1c 100644
--- a/packages/windows/installer/NTMakefile
+++ b/packages/windows/installer/NTMakefile
@@ -153,8 +153,8 @@ THIRDPARTYOBJS=$(INSTDIR)\apicache.wixobj $(INSTDIR)\lsacache.wixobj
 THIRDPARTYOPT=-dApiCache=1 -dLsaCache=1
 !endif
 
-!ifdef MKSHIMDIR
-THIRDPARTYOBJS=$(THIRDPARTYOBJS) $(MKSHIMDIR)\out\dest_$(OUTDIR)\install\MKShim.wixlib
+!if exist($(SRC)\thirdparty\MKShim)
+THIRDPARTYOBJS=$(THIRDPARTYOBJS) $(INSTDIR)\MKShim.wixlib
 THIRDPARTYOPT=$(THIRDPARTYOPT) -dMKShim=1
 !endif