diff --git a/direct/src/dist/commands.py b/direct/src/dist/commands.py
index 6564592a1a..6b64011f79 100644
--- a/direct/src/dist/commands.py
+++ b/direct/src/dist/commands.py
@@ -1408,17 +1408,22 @@ class bdist_apps(setuptools.Command):
         nsi.write('Section "" SecCore\n')
         nsi.write('  SetOutPath "$INSTDIR"\n')
         curdir = ""
+        nsi_dir = p3d.Filename.fromOsSpecific(build_cmd.build_base)
+        build_root_dir = p3d.Filename.fromOsSpecific(build_dir)
         for root, dirs, files in os.walk(build_dir):
             for name in files:
                 basefile = p3d.Filename.fromOsSpecific(os.path.join(root, name))
                 file = p3d.Filename(basefile)
                 file.makeAbsolute()
-                file.makeRelativeTo(build_dir)
-                outdir = file.getDirname().replace('/', '\\')
+                file.makeRelativeTo(nsi_dir)
+                outdir = p3d.Filename(basefile)
+                outdir.makeAbsolute()
+                outdir.makeRelativeTo(build_root_dir)
+                outdir = outdir.getDirname().replace('/', '\\')
                 if curdir != outdir:
                     nsi.write('  SetOutPath "$INSTDIR\\%s"\n' % outdir)
                     curdir = outdir
-                nsi.write('  File "%s"\n' % (basefile.toOsSpecific()))
+                nsi.write('  File "%s"\n' % (file.toOsSpecific()))
         nsi.write('  SetOutPath "$INSTDIR"\n')
         nsi.write('  WriteUninstaller "$INSTDIR\\Uninstall.exe"\n')
         nsi.write('  ; Start menu items\n')