diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index c2b0d67ff33a4b5515c5651eb781d1ff03dbab36..60c8d17a08d3fc63e5acc0e25ce26add23ab1dc7 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -1574,11 +1574,17 @@ ExecuteTruncate(TruncateStmt *stmt)
 	SubTransactionId mySubid;
 	ListCell   *cell;
 	List *partList = NIL;
+	List *relationsToTruncate = NIL;
+
+	/*
+	 * Copy list to ensure we do not modify a cached plan
+	 */
+	relationsToTruncate = list_copy(stmt->relations);
 
 	/*
 	 * Check if table has partitions and add them too
 	 */
-	foreach(cell, stmt->relations)
+	foreach(cell, relationsToTruncate)
 	{
 		RangeVar   *rv = lfirst(cell);
 		Relation	rel;
@@ -1596,12 +1602,12 @@ ExecuteTruncate(TruncateStmt *stmt)
 		heap_close(rel, NoLock);
 	}
 
-	stmt->relations = list_concat(partList, stmt->relations);
+	relationsToTruncate = list_concat(partList, relationsToTruncate);
 
 	/*
 	 * Open, exclusive-lock, and check all the explicitly-specified relations
 	 */
-	foreach(cell, stmt->relations)
+	foreach(cell, relationsToTruncate)
 	{
 		RangeVar   *rv = lfirst(cell);
 		Relation	rel;
diff --git a/src/test/regress/expected/partition_with_user_defined_function_that_truncates.out b/src/test/regress/expected/partition_with_user_defined_function_that_truncates.out
new file mode 100644
index 0000000000000000000000000000000000000000..d25f2706b414cdf775ebfa504b4630d88aeb62e4
--- /dev/null
+++ b/src/test/regress/expected/partition_with_user_defined_function_that_truncates.out
@@ -0,0 +1,60 @@
+-- Given there is a partitioned table
+	create table some_partitioned_table_to_truncate
+	(
+		a integer
+	)
+	partition by range (a) (
+		partition b start (0)
+	);
+NOTICE:  Table doesn't have 'DISTRIBUTED BY' clause -- Using column named 'a' as the Greenplum Database data distribution key for this table.
+HINT:  The 'DISTRIBUTED BY' clause determines the distribution of data. Make sure column(s) chosen are the optimal data distribution key to minimize skew.
+NOTICE:  CREATE TABLE will create partition "some_partitioned_table_to_truncate_1_prt_b" for table "some_partitioned_table_to_truncate"
+-- And a function that truncates the partitioned table
+	CREATE OR REPLACE FUNCTION truncate_a_partition_table() RETURNS VOID AS
+	$$
+	BEGIN
+	    TRUNCATE some_partitioned_table_to_truncate;
+	END;
+	$$ LANGUAGE plpgsql;
+-- When I truncate the table twice
+	insert into some_partitioned_table_to_truncate
+	       select i from generate_series(1, 10) i;
+   	select count(*) from some_partitioned_table_to_truncate;
+ count 
+-------
+    10
+(1 row)
+
+	select truncate_a_partition_table();
+ truncate_a_partition_table 
+----------------------------
+ 
+(1 row)
+
+   	select count(*) from some_partitioned_table_to_truncate;	
+ count 
+-------
+     0
+(1 row)
+
+-- Then I get the same result both times (no rows)
+	insert into some_partitioned_table_to_truncate
+	       select i from generate_series(1, 10) i;
+   	select count(*) from some_partitioned_table_to_truncate;
+ count 
+-------
+    10
+(1 row)
+
+	select truncate_a_partition_table();
+ truncate_a_partition_table 
+----------------------------
+ 
+(1 row)
+
+   	select count(*) from some_partitioned_table_to_truncate;	
+ count 
+-------
+     0
+(1 row)
+
diff --git a/src/test/regress/greenplum_schedule b/src/test/regress/greenplum_schedule
index e23a0d40d999957961f4b11e6cb2e586d617e381..5bfea59c1acbe0a3124dd1eb9b94f81f17f57bef 100755
--- a/src/test/regress/greenplum_schedule
+++ b/src/test/regress/greenplum_schedule
@@ -86,7 +86,7 @@ test: partial_table
 
 # 'partition' runs for a long time, so try to keep it together with other
 # long-running tests.
-test: partition partition1 partition_indexing parruleord partition_storage partition_ddl partition_with_user_defined_function partition_unlogged partition_subquery
+test: partition partition1 partition_indexing parruleord partition_storage partition_ddl partition_with_user_defined_function partition_unlogged partition_subquery partition_with_user_defined_function_that_truncates
 
 test: index_constraint_naming index_constraint_naming_partition index_constraint_naming_upgrade
 # 'partition_locking' gets confused if other backends run concurrently and
diff --git a/src/test/regress/sql/partition_with_user_defined_function_that_truncates.sql b/src/test/regress/sql/partition_with_user_defined_function_that_truncates.sql
new file mode 100644
index 0000000000000000000000000000000000000000..c373df07e8ef2a1f4587d7f422a461de1c200b77
--- /dev/null
+++ b/src/test/regress/sql/partition_with_user_defined_function_that_truncates.sql
@@ -0,0 +1,31 @@
+-- Given there is a partitioned table
+	create table some_partitioned_table_to_truncate
+	(
+		a integer
+	)
+	partition by range (a) (
+		partition b start (0)
+	);
+
+-- And a function that truncates the partitioned table
+	CREATE OR REPLACE FUNCTION truncate_a_partition_table() RETURNS VOID AS
+	$$
+	BEGIN
+	    TRUNCATE some_partitioned_table_to_truncate;
+	END;
+	$$ LANGUAGE plpgsql;
+
+-- When I truncate the table twice
+	insert into some_partitioned_table_to_truncate
+	       select i from generate_series(1, 10) i;
+   	select count(*) from some_partitioned_table_to_truncate;
+	select truncate_a_partition_table();
+   	select count(*) from some_partitioned_table_to_truncate;	
+
+-- Then I get the same result both times (no rows)
+	insert into some_partitioned_table_to_truncate
+	       select i from generate_series(1, 10) i;
+   	select count(*) from some_partitioned_table_to_truncate;
+	select truncate_a_partition_table();
+   	select count(*) from some_partitioned_table_to_truncate;	
+