diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 7588b422a3a..becbe19627b 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -291,11 +291,11 @@ static void ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
 			   IndexStmt *stmt, bool is_rebuild);
 static void ATExecAddConstraint(List **wqueue,
 					AlteredTableInfo *tab, Relation rel,
-					Node *newConstraint, bool recurse);
+					Node *newConstraint, bool recurse, bool is_readd);
 static void ATAddCheckConstraint(List **wqueue,
 					 AlteredTableInfo *tab, Relation rel,
 					 Constraint *constr,
-					 bool recurse, bool recursing);
+					 bool recurse, bool recursing, bool is_readd);
 static void ATAddForeignKeyConstraint(AlteredTableInfo *tab, Relation rel,
 						  FkConstraint *fkconstraint);
 static void ATExecDropConstraint(Relation rel, const char *constrName,
@@ -2559,10 +2559,13 @@ ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
 			ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, true);
 			break;
 		case AT_AddConstraint:	/* ADD CONSTRAINT */
-			ATExecAddConstraint(wqueue, tab, rel, cmd->def, false);
+			ATExecAddConstraint(wqueue, tab, rel, cmd->def, false, false);
 			break;
 		case AT_AddConstraintRecurse:	/* ADD CONSTRAINT with recursion */
-			ATExecAddConstraint(wqueue, tab, rel, cmd->def, true);
+			ATExecAddConstraint(wqueue, tab, rel, cmd->def, true, false);
+			break;
+		case AT_ReAddConstraint:	/* Re-add pre-existing check constraint */
+			ATExecAddConstraint(wqueue, tab, rel, cmd->def, false, true);
 			break;
 		case AT_DropConstraint:	/* DROP CONSTRAINT */
 			ATExecDropConstraint(rel, cmd->name, cmd->behavior, false, false);
@@ -4309,7 +4312,7 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
  */
 static void
 ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
-					Node *newConstraint, bool recurse)
+					Node *newConstraint, bool recurse, bool is_readd)
 {
 	switch (nodeTag(newConstraint))
 	{
@@ -4327,7 +4330,7 @@ ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 				{
 					case CONSTR_CHECK:
 						ATAddCheckConstraint(wqueue, tab, rel,
-											 constr, recurse, false);
+											 constr, recurse, false, is_readd);
 						break;
 					default:
 						elog(ERROR, "unrecognized constraint type: %d",
@@ -4387,10 +4390,18 @@ ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
  * AddRelationNewConstraints would normally assign different names to the
  * child constraints.  To fix that, we must capture the name assigned at
  * the parent table and pass that down.
+ *
+ * When re-adding a previously existing constraint (during ALTER COLUMN TYPE),
+ * we don't need to recurse here, because recursion will be carried out at a
+ * higher level; the constraint name issue doesn't apply because the names
+ * have already been assigned and are just being re-used.  We need a separate
+ * "is_readd" flag for that; just setting recurse=false would result in an
+ * error if there are child tables.
  */
 static void
 ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
-					 Constraint *constr, bool recurse, bool recursing)
+					 Constraint *constr, bool recurse, bool recursing,
+					 bool is_readd)
 {
 	List	   *newcons;
 	ListCell   *lcon;
@@ -4449,6 +4460,13 @@ ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 	if (newcons == NIL)
 		return;
 
+	/*
+	 * Also, in a re-add operation, we don't need to recurse (that will be
+	 * handled at higher levels).
+	 */
+	if (is_readd)
+		return;
+
 	/*
 	 * Propagate to children as appropriate.  Unlike most other ALTER
 	 * routines, we have to do this one level of recursion at a time; we can't
@@ -4481,7 +4499,7 @@ ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
 
 		/* Recurse to child */
 		ATAddCheckConstraint(wqueue, childtab, childrel,
-							 constr, recurse, true);
+							 constr, recurse, true, is_readd);
 
 		heap_close(childrel, NoLock);
 	}
@@ -6057,6 +6075,10 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 	/*
 	 * Attach each generated command to the proper place in the work queue.
 	 * Note this could result in creation of entirely new work-queue entries.
+	 *
+	 * Also note that we have to tweak the command subtypes, because it turns
+	 * out that re-creation of indexes and constraints has to act a bit
+	 * differently from initial creation.
 	 */
 	foreach(list_item, querytree_list)
 	{
@@ -6100,6 +6122,7 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 									lappend(tab->subcmds[AT_PASS_OLD_INDEX], cmd);
 								break;
 							case AT_AddConstraint:
+								cmd->subtype = AT_ReAddConstraint;
 								tab->subcmds[AT_PASS_OLD_CONSTR] =
 									lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
 								break;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index f27d9a26bda..7123a5a130f 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1131,7 +1131,9 @@ typedef enum AlterTableType
 	AT_EnableReplicaRule,		/* ENABLE REPLICA RULE name */
 	AT_DisableRule,				/* DISABLE RULE name */
 	AT_AddInherit,				/* INHERIT parent */
-	AT_DropInherit				/* NO INHERIT parent */
+	AT_DropInherit,				/* NO INHERIT parent */
+	/* this will be in a more natural position in 9.3: */
+	AT_ReAddConstraint			/* internal to commands/tablecmds.c */
 } AlterTableType;
 
 typedef struct AlterTableCmd	/* one subcommand of an ALTER TABLE */
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index e8887db00e9..f7f9e631b87 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -1456,6 +1456,27 @@ select * from another;
 (3 rows)
 
 drop table another;
+-- ALTER TYPE with a check constraint and a child table (bug before Nov 2012)
+CREATE TABLE test_inh_check (a float check (a > 10.2));
+CREATE TABLE test_inh_check_child() INHERITS(test_inh_check);
+ALTER TABLE test_inh_check ALTER COLUMN a TYPE numeric;
+\d test_inh_check
+Table "public.test_inh_check"
+ Column |  Type   | Modifiers 
+--------+---------+-----------
+ a      | numeric | 
+Check constraints:
+    "test_inh_check_a_check" CHECK (a::double precision > 10.2::double precision)
+
+\d test_inh_check_child
+Table "public.test_inh_check_child"
+ Column |  Type   | Modifiers 
+--------+---------+-----------
+ a      | numeric | 
+Check constraints:
+    "test_inh_check_a_check" CHECK (a::double precision > 10.2::double precision)
+Inherits: test_inh_check
+
 -- disallow recursive containment of row types
 create temp table recur1 (f1 int);
 alter table recur1 add column f2 recur1; -- fails
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 26b5f03c179..4375867f977 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -1081,6 +1081,13 @@ select * from another;
 
 drop table another;
 
+-- ALTER TYPE with a check constraint and a child table (bug before Nov 2012)
+CREATE TABLE test_inh_check (a float check (a > 10.2));
+CREATE TABLE test_inh_check_child() INHERITS(test_inh_check);
+ALTER TABLE test_inh_check ALTER COLUMN a TYPE numeric;
+\d test_inh_check
+\d test_inh_check_child
+
 -- disallow recursive containment of row types
 create temp table recur1 (f1 int);
 alter table recur1 add column f2 recur1; -- fails