diff --git a/yocto-poky/meta/classes/ptest.bbclass b/yocto-poky/meta/classes/ptest.bbclass
index 4dc5dbe..fa3561e 100644
--- a/yocto-poky/meta/classes/ptest.bbclass
+++ b/yocto-poky/meta/classes/ptest.bbclass
@@ -58,7 +58,7 @@
 
 python () {
     if not bb.data.inherits_class('native', d) and not bb.data.inherits_class('cross', d):
-        d.setVarFlag('do_install_ptest_base', 'fakeroot', 1)
+        d.setVarFlag('do_install_ptest_base', 'fakeroot', '1')
 
     # Remove all '*ptest_base' tasks when ptest is not enabled
     if not(d.getVar('PTEST_ENABLED', True) == "1"):