diff --git a/bitbake/lib/bb/parse/ast.py b/bitbake/lib/bb/parse/ast.py
index 5a086b4e95..ea1096f2de 100644
--- a/bitbake/lib/bb/parse/ast.py
+++ b/bitbake/lib/bb/parse/ast.py
@@ -340,9 +340,7 @@ class InheritDeferredNode(AstNode):
         self.inherit = (classes, filename, lineno)
 
     def eval(self, data):
-        inherits = data.getVar('__BBDEFINHERITS', False) or []
-        inherits.append(self.inherit)
-        data.setVar('__BBDEFINHERITS', inherits)
+        bb.parse.BBHandler.inherit_defer(*self.inherit, data)
 
 class AddFragmentsNode(AstNode):
     def __init__(self, filename, lineno, fragments_path_prefix, fragments_variable, flagged_variables_list_variable):
@@ -571,9 +569,7 @@ def multi_finalize(fn, d):
                 d.setVar("BBEXTENDVARIANT", variantmap[name])
             else:
                 d.setVar("PN", "%s-%s" % (pn, name))
-            inherits = d.getVar('__BBDEFINHERITS', False) or []
-            inherits.append((extendedmap[name], fn, 0))
-            d.setVar('__BBDEFINHERITS', inherits)
+            bb.parse.BBHandler.inherit_defer(extendedmap[name], fn, 0, d)
 
         safe_d.setVar("BBCLASSEXTEND", extended)
         _create_variants(datastores, extendedmap.keys(), extendfunc, onlyfinalise)
diff --git a/bitbake/lib/bb/parse/parse_py/BBHandler.py b/bitbake/lib/bb/parse/parse_py/BBHandler.py
index 4bdb11994f..008fec2308 100644
--- a/bitbake/lib/bb/parse/parse_py/BBHandler.py
+++ b/bitbake/lib/bb/parse/parse_py/BBHandler.py
@@ -42,12 +42,22 @@ def supports(fn, d):
     """Return True if fn has a supported extension"""
     return os.path.splitext(fn)[-1] in [".bb", ".bbclass", ".inc"]
 
+def inherit_defer(expression, fn, lineno, d):
+    inherit = (expression, fn, lineno)
+    inherits = d.getVar('__BBDEFINHERITS', False) or []
+    inherits.append(inherit)
+    d.setVar('__BBDEFINHERITS', inherits)
+
 def inherit(files, fn, lineno, d, deferred=False):
     __inherit_cache = d.getVar('__inherit_cache', False) or []
     #if "${" in files and not deferred:
     #    bb.warn("%s:%s has non deferred conditional inherit" % (fn, lineno))
     files = d.expand(files).split()
     for file in files:
+        defer = (d.getVar("BB_DEFER_BBCLASSES") or "").split()
+        if not deferred and file in defer:
+            inherit_defer(file, fn, lineno, d)
+            continue
         classtype = d.getVar("__bbclasstype", False)
         origfile = file
         for t in ["classes-" + classtype, "classes"]: