diff --git a/meta/lib/oeqa/selftest/cases/buildoptions.py b/meta/lib/oeqa/selftest/cases/buildoptions.py
index 767e19bd88..b46f55e256 100644
--- a/meta/lib/oeqa/selftest/cases/buildoptions.py
+++ b/meta/lib/oeqa/selftest/cases/buildoptions.py
@@ -173,11 +173,11 @@ class SourceMirroring(OESelftestTestCase):
     def test_yocto_source_mirror(self):
         self.write_config("""
 BB_ALLOWED_NETWORKS = "downloads.yoctoproject.org"
-MIRRORS = ""
+MIRRORS:forcevariable = ""
 DL_DIR = "${TMPDIR}/test_downloads"
 STAMPS_DIR = "${TMPDIR}/test_stamps"
 SSTATE_DIR = "${TMPDIR}/test_sstate-cache"
-PREMIRRORS = "\\
+PREMIRRORS:forcevariable = "\\
     bzr://.*/.*   http://downloads.yoctoproject.org/mirror/sources/ \\n \\
     cvs://.*/.*   http://downloads.yoctoproject.org/mirror/sources/ \\n \\
     git://.*/.*   http://downloads.yoctoproject.org/mirror/sources/ \\n \\