diff --git a/meta/classes/base.bbclass b/meta/classes/base.bbclass
index 27edea8af9..99748796e6 100644
--- a/meta/classes/base.bbclass
+++ b/meta/classes/base.bbclass
@@ -403,7 +403,7 @@ python () {
     #
     # These take the form:
     #
-    # PACKAGECONFIG ?? = "<default options>"
+    # PACKAGECONFIG ??= "<default options>"
     # PACKAGECONFIG[foo] = "--enable-foo,--disable-foo,foo_depends,foo_runtime_depends"
     pkgconfigflags = d.getVarFlags("PACKAGECONFIG") or {}
     if pkgconfigflags: