Look in db4 directories when checking for db4.
diff --git a/setup.py b/setup.py
index 5b11ad9..8c7563a 100644
--- a/setup.py
+++ b/setup.py
@@ -455,10 +455,10 @@
                                 '/usr/local/BerkeleyDB.4.2/include',
                                 '/usr/local/BerkeleyDB.4.1/include',
                                 '/usr/local/BerkeleyDB.4.0/include',
-                                '/usr/local/include/db3',
-                                '/opt/sfw/include/db3',
-                                '/sw/include/db3',
-                                '/usr/include/db3',
+                                '/usr/local/include/db4',
+                                '/opt/sfw/include/db4',
+                                '/sw/include/db4',
+                                '/usr/include/db4',
                                 ),
                     'incs': ('db_185.h',)},
             'db3': {'libs': ('db-3.3', 'db-3.2', 'db-3.1', 'db-3.0'),