diff --git a/python/javapackages/common/util.py b/python/javapackages/common/util.py
index 071805f..325650a 100644
--- a/python/javapackages/common/util.py
+++ b/python/javapackages/common/util.py
@@ -44,7 +44,7 @@ def kill_parent_process():
 def get_cachedir(path, create_if_not_exists=True):
     cachedir_path = os.path.join(path, ".javapackages_cache")
     if not os.path.exists(cachedir_path) and create_if_not_exists:
-        os.mkdir(cachedir_path)
+        os.makedirs(cachedir_path)
     return cachedir_path
 
 
diff --git a/python/javapackages/metadata/metadata.py b/python/javapackages/metadata/metadata.py
index 5b507e3..a0485d1 100644
--- a/python/javapackages/metadata/metadata.py
+++ b/python/javapackages/metadata/metadata.py
@@ -250,7 +250,8 @@ class Metadata(object):
     def _write_cache_file(self, cachefile, content):
         try:
             cachefile = open(cachefile, 'wb')
-            pickle.dump(content, cachefile)
+            cache = (os.getppid(), content)
+            pickle.dump(cache, cachefile)
             cachefile.close()
         except IOError:
             return None
@@ -260,8 +261,12 @@ class Metadata(object):
     def _read_cache_file(cachefile):
         try:
             cachefile = open(cachefile, 'rb')
-            content = pickle.load(cachefile)
+            cache = pickle.load(cachefile)
             cachefile.close()
+            # check if the cache was most likely created during current build
+            if cache[0] != os.getppid():
+                logging.warning("Cache is outdated, skipping")
+                return None
         except IOError:
             return None
-        return content
+        return cache[1]