diff --git a/NEWS b/NEWS
index 21f6d201..737d3a3f 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,8 @@ What's new in psycopg 2.5.4
 - Fixed segfault if COPY statements are executed instead of using the
   proper methods (:ticket:`#219`).
 - Don't ignore silently the `cursor.callproc` argument without a length.
+- Added a few errors missing from `~psycopg2.errorcodes`, defined by
+  PostgreSQL but not documented.
 
 
 What's new in psycopg 2.5.3
diff --git a/doc/src/errorcodes.rst b/doc/src/errorcodes.rst
index bfaaeb45..3fdd5499 100644
--- a/doc/src/errorcodes.rst
+++ b/doc/src/errorcodes.rst
@@ -49,7 +49,7 @@ An example of the available constants defined in the module:
     >>> errorcodes.UNDEFINED_TABLE
     '42P01'
 
-Constants representing all the error values documented by PostgreSQL versions
+Constants representing all the error values defined by PostgreSQL versions
 between 8.1 and 9.2 are included in the module.
 
 
diff --git a/lib/errorcodes.py b/lib/errorcodes.py
index 12c300f6..e004cac5 100644
--- a/lib/errorcodes.py
+++ b/lib/errorcodes.py
@@ -284,6 +284,10 @@ STATEMENT_COMPLETION_UNKNOWN = '40003'
 DEADLOCK_DETECTED = '40P01'
 
 # Class 42 - Syntax Error or Access Rule Violation
+UNDEFINED_PSTATEMENT = '26000'
+UNDEFINED_CURSOR = '34000'
+UNDEFINED_DATABASE = '3D000'
+UNDEFINED_SCHEMA = '3F000'
 SYNTAX_ERROR_OR_ACCESS_RULE_VIOLATION = '42000'
 INSUFFICIENT_PRIVILEGE = '42501'
 SYNTAX_ERROR = '42601'