diff --git a/meta/classes-recipe/populate_sdk_ext.bbclass b/meta/classes-recipe/populate_sdk_ext.bbclass
index 20dfdf02d4..36a3e9c836 100644
--- a/meta/classes-recipe/populate_sdk_ext.bbclass
+++ b/meta/classes-recipe/populate_sdk_ext.bbclass
@@ -345,7 +345,13 @@ def write_local_conf(d, baseoutpath, derivative, core_meta_subdir, uninative_che
             if bb.data.inherits_class('uninative', d):
                f.write('INHERIT += "%s"\n' % 'uninative')
                f.write('UNINATIVE_CHECKSUM[%s] = "%s"\n\n' % (d.getVar('BUILD_ARCH'), uninative_checksum))
-            f.write('CONF_VERSION = "%s"\n\n' % d.getVar('CONF_VERSION', False))
+
+            # CONF_VERSION may not be set, for example when using an empty local.conf
+            # generated with bitbake-setup, and it is not otherwise required to exist.
+            # Write it out only if it's defined.
+            conf_version = d.getVar('CONF_VERSION', False)
+            if conf_version is not None:
+                f.write('CONF_VERSION = "%s"\n\n' % conf_version)
 
             # Some classes are not suitable for SDK, remove them from INHERIT
             f.write('INHERIT:remove = "%s"\n' % d.getVar('ESDK_CLASS_INHERIT_DISABLE', False))