diff --git a/src/backend/catalog/Catalog.pm b/src/backend/catalog/Catalog.pm
index 0275795dea..ece0a934f0 100644
--- a/src/backend/catalog/Catalog.pm
+++ b/src/backend/catalog/Catalog.pm
@@ -44,6 +44,8 @@ sub ParseHeader
 	$catalog{columns}     = [];
 	$catalog{toasting}    = [];
 	$catalog{indexing}    = [];
+	$catalog{other_oids}  = [];
+	$catalog{foreign_keys} = [];
 	$catalog{client_code} = [];
 
 	open(my $ifh, '<', $input_file) || die "$input_file: $!";
@@ -118,6 +120,14 @@ sub ParseHeader
 				index_decl => $6
 			  };
 		}
+		elsif (/^DECLARE_OID_DEFINING_MACRO\(\s*(\w+),\s*(\d+)\)/)
+		{
+			push @{ $catalog{other_oids} },
+			  {
+				other_name => $1,
+				other_oid  => $2
+			  };
+		}
 		elsif (
 			/^DECLARE_(ARRAY_)?FOREIGN_KEY(_OPT)?\(\s*\(([^)]+)\),\s*(\w+),\s*\(([^)]+)\)\)/
 		  )
@@ -572,6 +582,10 @@ sub FindAllOidsFromHeaders
 		{
 			push @oids, $index->{index_oid};
 		}
+		foreach my $other (@{ $catalog->{other_oids} })
+		{
+			push @oids, $other->{other_oid};
+		}
 	}
 
 	return \@oids;
diff --git a/src/backend/catalog/catalog.c b/src/backend/catalog/catalog.c
index 520f77971b..d7e5c02f95 100644
--- a/src/backend/catalog/catalog.c
+++ b/src/backend/catalog/catalog.c
@@ -339,9 +339,11 @@ IsPinnedObject(Oid classId, Oid objectId)
 	 * robustness.
 	 */
 
-	/* template1 is not pinned */
+	/* template1, template0, postgres are not pinned */
 	if (classId == DatabaseRelationId &&
-		objectId == TemplateDbOid)
+		(objectId == TemplateDbOid ||
+		 objectId == Template0ObjectId ||
+		 objectId == PostgresObjectId))
 		return false;
 
 	/* the public namespace is not pinned */
diff --git a/src/backend/catalog/genbki.pl b/src/backend/catalog/genbki.pl
index 2d02b02267..f4ec6d6d40 100644
--- a/src/backend/catalog/genbki.pl
+++ b/src/backend/catalog/genbki.pl
@@ -472,7 +472,7 @@ EOM
 	  $catalog->{rowtype_oid_macro}, $catalog->{rowtype_oid}
 	  if $catalog->{rowtype_oid_macro};
 
-	# Likewise for macros for toast and index OIDs
+	# Likewise for macros for toast, index, and other OIDs
 	foreach my $toast (@{ $catalog->{toasting} })
 	{
 		printf $def "#define %s %s\n",
@@ -488,6 +488,12 @@ EOM
 		  $index->{index_oid_macro}, $index->{index_oid}
 		  if $index->{index_oid_macro};
 	}
+	foreach my $other (@{ $catalog->{other_oids} })
+	{
+		printf $def "#define %s %s\n",
+		  $other->{other_name}, $other->{other_oid}
+		  if $other->{other_name};
+	}
 
 	print $def "\n";
 
diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index 1cb4a5b0d2..5e2eeefc4c 100644
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -59,11 +59,11 @@
 #include "sys/mman.h"
 #endif
 
-#include "access/transam.h"
 #include "access/xlog_internal.h"
 #include "catalog/pg_authid_d.h"
 #include "catalog/pg_class_d.h" /* pgrminclude ignore */
 #include "catalog/pg_collation_d.h"
+#include "catalog/pg_database_d.h"	/* pgrminclude ignore */
 #include "common/file_perm.h"
 #include "common/file_utils.h"
 #include "common/logging.h"
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index d3588607e7..786d592e2b 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -2901,10 +2901,11 @@ dumpDatabase(Archive *fout)
 	qdatname = pg_strdup(fmtId(datname));
 
 	/*
-	 * Prepare the CREATE DATABASE command.  We must specify encoding, locale,
-	 * and tablespace since those can't be altered later.  Other DB properties
-	 * are left to the DATABASE PROPERTIES entry, so that they can be applied
-	 * after reconnecting to the target DB.
+	 * Prepare the CREATE DATABASE command.  We must specify OID (if we want
+	 * to preserve that), as well as the encoding, locale, and tablespace
+	 * since those can't be altered later.  Other DB properties are left to
+	 * the DATABASE PROPERTIES entry, so that they can be applied after
+	 * reconnecting to the target DB.
 	 */
 	if (dopt->binary_upgrade)
 	{
diff --git a/src/include/access/transam.h b/src/include/access/transam.h
index 9a2816de51..338dfca5a0 100644
--- a/src/include/access/transam.h
+++ b/src/include/access/transam.h
@@ -196,10 +196,6 @@ FullTransactionIdAdvance(FullTransactionId *dest)
 #define FirstUnpinnedObjectId	12000
 #define FirstNormalObjectId		16384
 
-/* OIDs of Template0 and Postgres database are fixed */
-#define Template0ObjectId		4
-#define PostgresObjectId		5
-
 /*
  * VariableCache is a data structure in shared memory that is used to track
  * OID and XID assignment state.  For largely historical reasons, there is
diff --git a/src/include/catalog/genbki.h b/src/include/catalog/genbki.h
index 4ecd76f4be..992b784236 100644
--- a/src/include/catalog/genbki.h
+++ b/src/include/catalog/genbki.h
@@ -84,6 +84,14 @@
 #define DECLARE_UNIQUE_INDEX(name,oid,oidmacro,decl) extern int no_such_variable
 #define DECLARE_UNIQUE_INDEX_PKEY(name,oid,oidmacro,decl) extern int no_such_variable
 
+/*
+ * These lines inform genbki.pl about manually-assigned OIDs that do not
+ * correspond to any entry in the catalog *.dat files, but should be subject
+ * to uniqueness verification and renumber_oids.pl renumbering.  A C macro
+ * to #define the given name is emitted into the corresponding *_d.h file.
+ */
+#define DECLARE_OID_DEFINING_MACRO(name,oid) extern int no_such_variable
+
 /*
  * These lines are processed by genbki.pl to create a table for use
  * by the pg_get_catalog_foreign_keys() function.  We do not have any
diff --git a/src/include/catalog/pg_database.h b/src/include/catalog/pg_database.h
index e10e91c0af..96be9e9729 100644
--- a/src/include/catalog/pg_database.h
+++ b/src/include/catalog/pg_database.h
@@ -91,4 +91,13 @@ DECLARE_TOAST_WITH_MACRO(pg_database, 4177, 4178, PgDatabaseToastTable, PgDataba
 DECLARE_UNIQUE_INDEX(pg_database_datname_index, 2671, DatabaseNameIndexId, on pg_database using btree(datname name_ops));
 DECLARE_UNIQUE_INDEX_PKEY(pg_database_oid_index, 2672, DatabaseOidIndexId, on pg_database using btree(oid oid_ops));
 
+/*
+ * pg_database.dat contains an entry for template1, but not for the template0
+ * or postgres databases, because those are created later in initdb.
+ * However, we still want to manually assign the OIDs for template0 and
+ * postgres, so declare those here.
+ */
+DECLARE_OID_DEFINING_MACRO(Template0ObjectId, 4);
+DECLARE_OID_DEFINING_MACRO(PostgresObjectId, 5);
+
 #endif							/* PG_DATABASE_H */
diff --git a/src/include/catalog/renumber_oids.pl b/src/include/catalog/renumber_oids.pl
index 7de13da4bd..ba8c69c87e 100755
--- a/src/include/catalog/renumber_oids.pl
+++ b/src/include/catalog/renumber_oids.pl
@@ -170,6 +170,16 @@ foreach my $input_file (@header_files)
 				$changed = 1;
 			}
 		}
+		elsif (/^(DECLARE_OID_DEFINING_MACRO\(\s*\w+,\s*)(\d+)\)/)
+		{
+			if (exists $maphash{$2})
+			{
+				my $repl = $1 . $maphash{$2} . ")";
+				$line =~
+				  s/^DECLARE_OID_DEFINING_MACRO\(\s*\w+,\s*\d+\)/$repl/;
+				$changed = 1;
+			}
+		}
 		elsif ($line =~ m/^CATALOG\((\w+),(\d+),(\w+)\)/)
 		{
 			if (exists $maphash{$2})
diff --git a/src/include/catalog/unused_oids b/src/include/catalog/unused_oids
index 61d41e7561..e55bc6fa3c 100755
--- a/src/include/catalog/unused_oids
+++ b/src/include/catalog/unused_oids
@@ -32,15 +32,6 @@ my @input_files = glob("pg_*.h");
 
 my $oids = Catalog::FindAllOidsFromHeaders(@input_files);
 
-# Push the template0 and postgres database OIDs.
-my $Template0ObjectId =
-  Catalog::FindDefinedSymbol('access/transam.h', '..', 'Template0ObjectId');
-push @{$oids}, $Template0ObjectId;
-
-my $PostgresObjectId =
-  Catalog::FindDefinedSymbol('access/transam.h', '..', 'PostgresObjectId');
-push @{$oids}, $PostgresObjectId;
-
 # Also push FirstGenbkiObjectId to serve as a terminator for the last gap.
 my $FirstGenbkiObjectId =
   Catalog::FindDefinedSymbol('access/transam.h', '..', 'FirstGenbkiObjectId');