diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index a1137a3bf09..843ed48aa76 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -10939,6 +10939,12 @@ ATExecPartedIdxSetTableSpace(Relation rel, Oid newTableSpace)
 
 	Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX);
 
+	/* Can't allow a non-shared relation in pg_global */
+	if (newTableSpace == GLOBALTABLESPACE_OID)
+		ereport(ERROR,
+		(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+			errmsg("only shared relations can be placed in pg_global tablespace")));
+
 	/*
 	 * No work if no change in tablespace.
 	 */
diff --git a/src/test/regress/input/tablespace.source b/src/test/regress/input/tablespace.source
index 60c87261db8..2ac757cfab2 100644
--- a/src/test/regress/input/tablespace.source
+++ b/src/test/regress/input/tablespace.source
@@ -101,6 +101,7 @@ CREATE UNIQUE INDEX anindex ON testschema.atable(column1);
 
 ALTER TABLE testschema.atable SET TABLESPACE regress_tblspace;
 ALTER INDEX testschema.anindex SET TABLESPACE regress_tblspace;
+ALTER INDEX testschema.part_a_idx SET TABLESPACE pg_global;
 ALTER INDEX testschema.part_a_idx SET TABLESPACE pg_default;
 ALTER INDEX testschema.part_a_idx SET TABLESPACE regress_tblspace;
 
diff --git a/src/test/regress/output/tablespace.source b/src/test/regress/output/tablespace.source
index 43962e6f013..2e78e5ece68 100644
--- a/src/test/regress/output/tablespace.source
+++ b/src/test/regress/output/tablespace.source
@@ -214,6 +214,8 @@ CREATE TABLE testschema.atable AS VALUES (1), (2);
 CREATE UNIQUE INDEX anindex ON testschema.atable(column1);
 ALTER TABLE testschema.atable SET TABLESPACE regress_tblspace;
 ALTER INDEX testschema.anindex SET TABLESPACE regress_tblspace;
+ALTER INDEX testschema.part_a_idx SET TABLESPACE pg_global;
+ERROR:  only shared relations can be placed in pg_global tablespace
 ALTER INDEX testschema.part_a_idx SET TABLESPACE pg_default;
 ALTER INDEX testschema.part_a_idx SET TABLESPACE regress_tblspace;
 INSERT INTO testschema.atable VALUES(3);	-- ok