diff --git a/pelican/__init__.py b/pelican/__init__.py
index d5cf2d04..edd30968 100644
--- a/pelican/__init__.py
+++ b/pelican/__init__.py
@@ -65,8 +65,8 @@ class Pelican(object):
 
         # erase the directory if it is not the source and if that's 
         # explicitely asked
-        if (self.delete_outputdir and 
-                os.path.realpath(self.path).startswith(self.output_path)):
+        if (self.delete_outputdir and not
+                os.path.realpath(self.path).startswith(self.output_path)): 
             clean_output_dir(self.output_path)
 
         writer = self.get_writer()