diff --git a/make_rpm7.py b/make_rpm7.py
index cf2b271..be7ce0f 100755
--- a/make_rpm7.py
+++ b/make_rpm7.py
@@ -70,7 +70,7 @@ class build(object):
     if os.path.exists( os.path.join( specdir, specname ) ):
       return specname
     specname = 'lts.spec'
-    specname = 'lts' + str(os.getenv( "BUILD_VERSION" )) + '.spec'
+    specname = 'lts' + str(os.getenv( "OS_VERSION" )) + '.spec'
     debug( "specname: %s" % os.path.join( specdir, specname ) )
     if os.path.exists( os.path.join( specdir, specname ) ):
       return specname