diff --git a/poky/scripts/lib/devtool/upgrade.py b/poky/scripts/lib/devtool/upgrade.py
index 18c5b66..cb6dce3 100644
--- a/poky/scripts/lib/devtool/upgrade.py
+++ b/poky/scripts/lib/devtool/upgrade.py
@@ -32,7 +32,7 @@
 
 def _get_srctree(tmpdir):
     srctree = tmpdir
-    dirs = os.listdir(tmpdir)
+    dirs = scriptutils.filter_src_subdirs(tmpdir)
     if len(dirs) == 1:
         srctree = os.path.join(tmpdir, dirs[0])
     return srctree
@@ -281,7 +281,8 @@
             logger.info('Preserving temporary directory %s' % tmpsrctree)
         else:
             shutil.rmtree(tmpsrctree)
-            shutil.rmtree(tmpdir)
+            if tmpdir != tmpsrctree:
+                shutil.rmtree(tmpdir)
 
     return (rev, md5, sha256, srcbranch, srcsubdir_rel)