diff --git a/bitbake/lib/bb/data.py b/bitbake/lib/bb/data.py
index 9a32353..dc5a425 100644
--- a/bitbake/lib/bb/data.py
+++ b/bitbake/lib/bb/data.py
@@ -357,6 +357,8 @@ def generate_dependencies(d):
 
 def inherits_class(klass, d):
     val = getVar('__inherit_cache', d) or []
-    if os.path.join('classes', '%s.bbclass' % klass) in val:
-        return True
+    needle = os.path.join('classes', '%s.bbclass' % klass)
+    for v in val:
+        if v.endswith(needle):
+            return True
     return False
diff --git a/bitbake/lib/bb/parse/parse_py/BBHandler.py b/bitbake/lib/bb/parse/parse_py/BBHandler.py
index 92c55f5..e6039e1 100644
--- a/bitbake/lib/bb/parse/parse_py/BBHandler.py
+++ b/bitbake/lib/bb/parse/parse_py/BBHandler.py
@@ -74,6 +74,13 @@ def inherit(files, fn, lineno, d):
         if not os.path.isabs(file) and not file.endswith(".bbclass"):
             file = os.path.join('classes', '%s.bbclass' % file)
 
+        if not os.path.isabs(file):
+            dname = os.path.dirname(fn)
+            bbpath = "%s:%s" % (dname, d.getVar("BBPATH", True))
+            abs_fn = bb.utils.which(bbpath, file)
+            if abs_fn:
+                file = abs_fn
+
         if not file in __inherit_cache:
             logger.log(logging.DEBUG -1, "BB %s:%d: inheriting %s", fn, lineno, file)
             __inherit_cache.append( file )