diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index 78b0f43..90dbf52 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -4467,7 +4467,7 @@ postgresImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid)
 								   "  attname, "
 								   "  format_type(atttypid, atttypmod), "
 								   "  attnotnull, "
-								   "  pg_get_expr(adbin, adrelid), "
+								   "  pg_get_expr(adbin, 0), "
 								   "  collname, "
 								   "  collnsp.nspname "
 								   "FROM pg_class c "
@@ -4488,7 +4488,7 @@ postgresImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid)
 								   "  attname, "
 								   "  format_type(atttypid, atttypmod), "
 								   "  attnotnull, "
-								   "  pg_get_expr(adbin, adrelid), "
+								   "  pg_get_expr(adbin, 0), "
 								   "  NULL, NULL "
 								   "FROM pg_class c "
 								   "  JOIN pg_namespace n ON "
diff --git a/src/backend/catalog/information_schema.sql b/src/backend/catalog/information_schema.sql
index f4e69f4..23b552c 100644
--- a/src/backend/catalog/information_schema.sql
+++ b/src/backend/catalog/information_schema.sql
@@ -299,7 +299,7 @@ CREATE VIEW attributes AS
            CAST(c.relname AS sql_identifier) AS udt_name,
            CAST(a.attname AS sql_identifier) AS attribute_name,
            CAST(a.attnum AS cardinal_number) AS ordinal_position,
-           CAST(pg_get_expr(ad.adbin, ad.adrelid) AS character_data) AS attribute_default,
+           CAST(pg_get_expr(ad.adbin, 0) AS character_data) AS attribute_default,
            CAST(CASE WHEN a.attnotnull OR (t.typtype = 'd' AND t.typnotnull) THEN 'NO' ELSE 'YES' END
              AS yes_or_no)
              AS is_nullable, -- This column was apparently removed between SQL:2003 and SQL:2008.
@@ -656,7 +656,7 @@ CREATE VIEW columns AS
            CAST(c.relname AS sql_identifier) AS table_name,
            CAST(a.attname AS sql_identifier) AS column_name,
            CAST(a.attnum AS cardinal_number) AS ordinal_position,
-           CAST(pg_get_expr(ad.adbin, ad.adrelid) AS character_data) AS column_default,
+           CAST(pg_get_expr(ad.adbin, 0) AS character_data) AS column_default,
            CAST(CASE WHEN a.attnotnull OR (t.typtype = 'd' AND t.typnotnull) THEN 'NO' ELSE 'YES' END
              AS yes_or_no)
              AS is_nullable,
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index ea2f022..f1db915 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -8331,11 +8331,23 @@ getTableAttrs(Archive *fout, TableInfo *tblinfo, int numTables)
 						  tbinfo->dobj.namespace->dobj.name,
 						  tbinfo->dobj.name);
 
-			printfPQExpBuffer(q, "SELECT tableoid, oid, adnum, "
-							  "pg_catalog.pg_get_expr(adbin, adrelid) AS adsrc "
-							  "FROM pg_catalog.pg_attrdef "
-							  "WHERE adrelid = '%u'::pg_catalog.oid",
-							  tbinfo->dobj.catId.oid);
+			if (fout->remoteVersion >= 80400)
+			{
+				printfPQExpBuffer(q, "SELECT tableoid, oid, adnum, "
+								  "pg_catalog.pg_get_expr(adbin, 0) AS adsrc "
+								  "FROM pg_catalog.pg_attrdef "
+								  "WHERE adrelid = '%u'::pg_catalog.oid",
+								  tbinfo->dobj.catId.oid);
+			}
+			else
+			{
+				/* Before 8.4, pg_get_expr does not allow 0 for its second arg */
+				printfPQExpBuffer(q, "SELECT tableoid, oid, adnum, "
+								  "pg_catalog.pg_get_expr(adbin, 'pg_catalog.pg_type'::pg_catalog.regclass) AS adsrc "
+								  "FROM pg_catalog.pg_attrdef "
+								  "WHERE adrelid = '%u'::pg_catalog.oid",
+								  tbinfo->dobj.catId.oid);
+			}
 
 			res = ExecuteSqlQuery(fout, q->data, PGRES_TUPLES_OK);
 
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e5b3c1e..5a57db5 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -1728,7 +1728,7 @@ describeOneTableDetails(const char *schemaname,
 	 */
 	printfPQExpBuffer(&buf, "SELECT a.attname,");
 	appendPQExpBufferStr(&buf, "\n  pg_catalog.format_type(a.atttypid, a.atttypmod),"
-						 "\n  (SELECT substring(pg_catalog.pg_get_expr(d.adbin, d.adrelid) for 128)"
+						 "\n  (SELECT substring(pg_catalog.pg_get_expr(d.adbin, 0) for 128)"
 						 "\n   FROM pg_catalog.pg_attrdef d"
 						 "\n   WHERE d.adrelid = a.attrelid AND d.adnum = a.attnum AND a.atthasdef),"
 						 "\n  a.attnotnull, a.attnum,");