diff --git a/linecache.py b/linecache.py
index 4838625..d5bcc47 100644
--- a/linecache.py
+++ b/linecache.py
@@ -79,6 +79,9 @@ def updatecache(filename, module_globals=None):
     try:
         stat = os.stat(fullname)
     except os.error, msg:
+        if os.path.isabs(filename):
+            return []
+
         basename = os.path.split(filename)[1]
 
         # Try for a __loader__, if available
@@ -110,7 +113,7 @@ def updatecache(filename, module_globals=None):
             # When using imputil, sys.path may contain things other than
             # strings; ignore them when it happens.
             try:
-                fullname = os.path.join(dirname, basename)
+                fullname = os.path.join(dirname, filename)
             except (TypeError, AttributeError):
                 # Not sufficiently string-like to do anything useful with.
                 pass