diff --git a/contrib/jsonb_plperl/expected/jsonb_plperl.out b/contrib/jsonb_plperl/expected/jsonb_plperl.out
index e4f3cdd41a..d2d90eb483 100644
--- a/contrib/jsonb_plperl/expected/jsonb_plperl.out
+++ b/contrib/jsonb_plperl/expected/jsonb_plperl.out
@@ -52,16 +52,19 @@ SELECT testRegexpResultToJsonb();
  0
 (1 row)
 
-CREATE FUNCTION roundtrip(val jsonb) RETURNS jsonb
+CREATE FUNCTION roundtrip(val jsonb, ref text = '') RETURNS jsonb
 LANGUAGE plperl
 TRANSFORM FOR TYPE jsonb
 AS $$
+# can't use Data::Dumper, but let's at least check for unexpected ref type
+die 'unexpected '.(ref($_[0]) || 'not a').' reference'
+    if ref($_[0]) ne $_[1];
 return $_[0];
 $$;
-SELECT roundtrip('null');
- roundtrip 
------------
- null
+SELECT roundtrip('null') is null;
+ ?column? 
+----------
+ t
 (1 row)
 
 SELECT roundtrip('1');
@@ -115,91 +118,97 @@ SELECT roundtrip('false');
  0
 (1 row)
 
-SELECT roundtrip('[]');
+SELECT roundtrip('[]', 'ARRAY');
  roundtrip 
 -----------
  []
 (1 row)
 
-SELECT roundtrip('[null, null]');
+SELECT roundtrip('[null, null]', 'ARRAY');
   roundtrip   
 --------------
  [null, null]
 (1 row)
 
-SELECT roundtrip('[1, 2, 3]');
+SELECT roundtrip('[1, 2, 3]', 'ARRAY');
  roundtrip 
 -----------
  [1, 2, 3]
 (1 row)
 
-SELECT roundtrip('[-1, 2, -3]');
+SELECT roundtrip('[-1, 2, -3]', 'ARRAY');
   roundtrip  
 -------------
  [-1, 2, -3]
 (1 row)
 
-SELECT roundtrip('[1.2, 2.3, 3.4]');
+SELECT roundtrip('[1.2, 2.3, 3.4]', 'ARRAY');
     roundtrip    
 -----------------
  [1.2, 2.3, 3.4]
 (1 row)
 
-SELECT roundtrip('[-1.2, 2.3, -3.4]');
+SELECT roundtrip('[-1.2, 2.3, -3.4]', 'ARRAY');
      roundtrip     
 -------------------
  [-1.2, 2.3, -3.4]
 (1 row)
 
-SELECT roundtrip('["string1", "string2"]');
+SELECT roundtrip('["string1", "string2"]', 'ARRAY');
        roundtrip        
 ------------------------
  ["string1", "string2"]
 (1 row)
 
-SELECT roundtrip('{}');
+SELECT roundtrip('[["string1", "string2"]]', 'ARRAY');
+        roundtrip         
+--------------------------
+ [["string1", "string2"]]
+(1 row)
+
+SELECT roundtrip('{}', 'HASH');
  roundtrip 
 -----------
  {}
 (1 row)
 
-SELECT roundtrip('{"1": null}');
+SELECT roundtrip('{"1": null}', 'HASH');
   roundtrip  
 -------------
  {"1": null}
 (1 row)
 
-SELECT roundtrip('{"1": 1}');
+SELECT roundtrip('{"1": 1}', 'HASH');
  roundtrip 
 -----------
  {"1": 1}
 (1 row)
 
-SELECT roundtrip('{"1": -1}');
+SELECT roundtrip('{"1": -1}', 'HASH');
  roundtrip 
 -----------
  {"1": -1}
 (1 row)
 
-SELECT roundtrip('{"1": 1.1}');
+SELECT roundtrip('{"1": 1.1}', 'HASH');
  roundtrip  
 ------------
  {"1": 1.1}
 (1 row)
 
-SELECT roundtrip('{"1": -1.1}');
+SELECT roundtrip('{"1": -1.1}', 'HASH');
   roundtrip  
 -------------
  {"1": -1.1}
 (1 row)
 
-SELECT roundtrip('{"1": "string1"}');
+SELECT roundtrip('{"1": "string1"}', 'HASH');
     roundtrip     
 ------------------
  {"1": "string1"}
 (1 row)
 
-SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}');
+SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}', 'HASH');
             roundtrip            
 ---------------------------------
  {"1": {"2": [3, 4, 5]}, "2": 3}
diff --git a/contrib/jsonb_plperl/expected/jsonb_plperlu.out b/contrib/jsonb_plperl/expected/jsonb_plperlu.out
index b44995058f..3f5c5c681d 100644
--- a/contrib/jsonb_plperl/expected/jsonb_plperlu.out
+++ b/contrib/jsonb_plperl/expected/jsonb_plperlu.out
@@ -52,154 +52,192 @@ SELECT testRegexpResultToJsonb();
  0
 (1 row)
 
-CREATE FUNCTION roundtrip(val jsonb) RETURNS jsonb
+CREATE FUNCTION roundtrip(val jsonb, ref text = '') RETURNS jsonb
 LANGUAGE plperlu
 TRANSFORM FOR TYPE jsonb
 AS $$
+use Data::Dumper;
+$Data::Dumper::Sortkeys = 1;
+$Data::Dumper::Indent = 0;
+elog(INFO, Dumper($_[0]));
+die 'unexpected '.(ref($_[0]) || 'not a').' reference'
+    if ref($_[0]) ne $_[1];
 return $_[0];
 $$;
-SELECT roundtrip('null');
- roundtrip 
------------
- null
+SELECT roundtrip('null') is null;
+INFO:  $VAR1 = undef;
+ ?column? 
+----------
+ t
 (1 row)
 
 SELECT roundtrip('1');
+INFO:  $VAR1 = '1';
  roundtrip 
 -----------
  1
 (1 row)
 
 SELECT roundtrip('1E+131071');
+INFO:  $VAR1 = 'inf';
 ERROR:  cannot convert infinity to jsonb
 CONTEXT:  PL/Perl function "roundtrip"
 SELECT roundtrip('-1');
+INFO:  $VAR1 = '-1';
  roundtrip 
 -----------
  -1
 (1 row)
 
 SELECT roundtrip('1.2');
+INFO:  $VAR1 = '1.2';
  roundtrip 
 -----------
  1.2
 (1 row)
 
 SELECT roundtrip('-1.2');
+INFO:  $VAR1 = '-1.2';
  roundtrip 
 -----------
  -1.2
 (1 row)
 
 SELECT roundtrip('"string"');
+INFO:  $VAR1 = 'string';
  roundtrip 
 -----------
  "string"
 (1 row)
 
 SELECT roundtrip('"NaN"');
+INFO:  $VAR1 = 'NaN';
  roundtrip 
 -----------
  "NaN"
 (1 row)
 
 SELECT roundtrip('true');
+INFO:  $VAR1 = '1';
  roundtrip 
 -----------
  1
 (1 row)
 
 SELECT roundtrip('false');
+INFO:  $VAR1 = '0';
  roundtrip 
 -----------
  0
 (1 row)
 
-SELECT roundtrip('[]');
+SELECT roundtrip('[]', 'ARRAY');
+INFO:  $VAR1 = [];
  roundtrip 
 -----------
  []
 (1 row)
 
-SELECT roundtrip('[null, null]');
+SELECT roundtrip('[null, null]', 'ARRAY');
+INFO:  $VAR1 = [undef,undef];
   roundtrip   
 --------------
  [null, null]
 (1 row)
 
-SELECT roundtrip('[1, 2, 3]');
+SELECT roundtrip('[1, 2, 3]', 'ARRAY');
+INFO:  $VAR1 = ['1','2','3'];
  roundtrip 
 -----------
  [1, 2, 3]
 (1 row)
 
-SELECT roundtrip('[-1, 2, -3]');
+SELECT roundtrip('[-1, 2, -3]', 'ARRAY');
+INFO:  $VAR1 = ['-1','2','-3'];
   roundtrip  
 -------------
  [-1, 2, -3]
 (1 row)
 
-SELECT roundtrip('[1.2, 2.3, 3.4]');
+SELECT roundtrip('[1.2, 2.3, 3.4]', 'ARRAY');
+INFO:  $VAR1 = ['1.2','2.3','3.4'];
     roundtrip    
 -----------------
  [1.2, 2.3, 3.4]
 (1 row)
 
-SELECT roundtrip('[-1.2, 2.3, -3.4]');
+SELECT roundtrip('[-1.2, 2.3, -3.4]', 'ARRAY');
+INFO:  $VAR1 = ['-1.2','2.3','-3.4'];
      roundtrip     
 -------------------
  [-1.2, 2.3, -3.4]
 (1 row)
 
-SELECT roundtrip('["string1", "string2"]');
+SELECT roundtrip('["string1", "string2"]', 'ARRAY');
+INFO:  $VAR1 = ['string1','string2'];
        roundtrip        
 ------------------------
  ["string1", "string2"]
 (1 row)
 
-SELECT roundtrip('{}');
+SELECT roundtrip('[["string1", "string2"]]', 'ARRAY');
+INFO:  $VAR1 = [['string1','string2']];
+        roundtrip         
+--------------------------
+ [["string1", "string2"]]
+(1 row)
+
+SELECT roundtrip('{}', 'HASH');
+INFO:  $VAR1 = {};
  roundtrip 
 -----------
  {}
 (1 row)
 
-SELECT roundtrip('{"1": null}');
+SELECT roundtrip('{"1": null}', 'HASH');
+INFO:  $VAR1 = {'1' => undef};
   roundtrip  
 -------------
  {"1": null}
 (1 row)
 
-SELECT roundtrip('{"1": 1}');
+SELECT roundtrip('{"1": 1}', 'HASH');
+INFO:  $VAR1 = {'1' => '1'};
  roundtrip 
 -----------
  {"1": 1}
 (1 row)
 
-SELECT roundtrip('{"1": -1}');
+SELECT roundtrip('{"1": -1}', 'HASH');
+INFO:  $VAR1 = {'1' => '-1'};
  roundtrip 
 -----------
  {"1": -1}
 (1 row)
 
-SELECT roundtrip('{"1": 1.1}');
+SELECT roundtrip('{"1": 1.1}', 'HASH');
+INFO:  $VAR1 = {'1' => '1.1'};
  roundtrip  
 ------------
  {"1": 1.1}
 (1 row)
 
-SELECT roundtrip('{"1": -1.1}');
+SELECT roundtrip('{"1": -1.1}', 'HASH');
+INFO:  $VAR1 = {'1' => '-1.1'};
   roundtrip  
 -------------
  {"1": -1.1}
 (1 row)
 
-SELECT roundtrip('{"1": "string1"}');
+SELECT roundtrip('{"1": "string1"}', 'HASH');
+INFO:  $VAR1 = {'1' => 'string1'};
     roundtrip     
 ------------------
  {"1": "string1"}
 (1 row)
 
-SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}');
+SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}', 'HASH');
+INFO:  $VAR1 = {'1' => {'2' => ['3','4','5']},'2' => '3'};
             roundtrip            
 ---------------------------------
  {"1": {"2": [3, 4, 5]}, "2": 3}
diff --git a/contrib/jsonb_plperl/jsonb_plperl.c b/contrib/jsonb_plperl/jsonb_plperl.c
index bde93a71fc..1b63fc4b30 100644
--- a/contrib/jsonb_plperl/jsonb_plperl.c
+++ b/contrib/jsonb_plperl/jsonb_plperl.c
@@ -26,7 +26,7 @@ JsonbValue_to_SV(JsonbValue *jbv)
 	switch (jbv->type)
 	{
 		case jbvBinary:
-			return newRV(Jsonb_to_SV(jbv->val.binary.data));
+			return Jsonb_to_SV(jbv->val.binary.data);
 
 		case jbvNumeric:
 			{
@@ -83,7 +83,7 @@ Jsonb_to_SV(JsonbContainer *jsonb)
 					(r = JsonbIteratorNext(&it, &tmp, true)) != WJB_DONE)
 					elog(ERROR, "unexpected jsonb token: %d", r);
 
-				return newRV(JsonbValue_to_SV(&v));
+				return JsonbValue_to_SV(&v);
 			}
 			else
 			{
@@ -95,7 +95,7 @@ Jsonb_to_SV(JsonbContainer *jsonb)
 						av_push(av, JsonbValue_to_SV(&v));
 				}
 
-				return (SV *) av;
+				return newRV((SV *) av);
 			}
 
 		case WJB_BEGIN_OBJECT:
@@ -120,7 +120,7 @@ Jsonb_to_SV(JsonbContainer *jsonb)
 					}
 				}
 
-				return (SV *) hv;
+				return newRV((SV *) hv);
 			}
 
 		default:
@@ -268,7 +268,7 @@ jsonb_to_plperl(PG_FUNCTION_ARGS)
 	Jsonb	   *in = PG_GETARG_JSONB_P(0);
 	SV		   *sv = Jsonb_to_SV(&in->root);
 
-	return PointerGetDatum(newRV(sv));
+	return PointerGetDatum(sv);
 }
 
 
diff --git a/contrib/jsonb_plperl/sql/jsonb_plperl.sql b/contrib/jsonb_plperl/sql/jsonb_plperl.sql
index 8b0a8764af..642a71deb7 100644
--- a/contrib/jsonb_plperl/sql/jsonb_plperl.sql
+++ b/contrib/jsonb_plperl/sql/jsonb_plperl.sql
@@ -45,15 +45,18 @@ $$;
 SELECT testRegexpResultToJsonb();
 
 
-CREATE FUNCTION roundtrip(val jsonb) RETURNS jsonb
+CREATE FUNCTION roundtrip(val jsonb, ref text = '') RETURNS jsonb
 LANGUAGE plperl
 TRANSFORM FOR TYPE jsonb
 AS $$
+# can't use Data::Dumper, but let's at least check for unexpected ref type
+die 'unexpected '.(ref($_[0]) || 'not a').' reference'
+    if ref($_[0]) ne $_[1];
 return $_[0];
 $$;
 
 
-SELECT roundtrip('null');
+SELECT roundtrip('null') is null;
 SELECT roundtrip('1');
 SELECT roundtrip('1E+131071');
 SELECT roundtrip('-1');
@@ -65,23 +68,24 @@ SELECT roundtrip('"NaN"');
 SELECT roundtrip('true');
 SELECT roundtrip('false');
 
-SELECT roundtrip('[]');
-SELECT roundtrip('[null, null]');
-SELECT roundtrip('[1, 2, 3]');
-SELECT roundtrip('[-1, 2, -3]');
-SELECT roundtrip('[1.2, 2.3, 3.4]');
-SELECT roundtrip('[-1.2, 2.3, -3.4]');
-SELECT roundtrip('["string1", "string2"]');
+SELECT roundtrip('[]', 'ARRAY');
+SELECT roundtrip('[null, null]', 'ARRAY');
+SELECT roundtrip('[1, 2, 3]', 'ARRAY');
+SELECT roundtrip('[-1, 2, -3]', 'ARRAY');
+SELECT roundtrip('[1.2, 2.3, 3.4]', 'ARRAY');
+SELECT roundtrip('[-1.2, 2.3, -3.4]', 'ARRAY');
+SELECT roundtrip('["string1", "string2"]', 'ARRAY');
+SELECT roundtrip('[["string1", "string2"]]', 'ARRAY');
 
-SELECT roundtrip('{}');
-SELECT roundtrip('{"1": null}');
-SELECT roundtrip('{"1": 1}');
-SELECT roundtrip('{"1": -1}');
-SELECT roundtrip('{"1": 1.1}');
-SELECT roundtrip('{"1": -1.1}');
-SELECT roundtrip('{"1": "string1"}');
+SELECT roundtrip('{}', 'HASH');
+SELECT roundtrip('{"1": null}', 'HASH');
+SELECT roundtrip('{"1": 1}', 'HASH');
+SELECT roundtrip('{"1": -1}', 'HASH');
+SELECT roundtrip('{"1": 1.1}', 'HASH');
+SELECT roundtrip('{"1": -1.1}', 'HASH');
+SELECT roundtrip('{"1": "string1"}', 'HASH');
 
-SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}');
+SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}', 'HASH');
 
 
 \set VERBOSITY terse \\ -- suppress cascade details
diff --git a/contrib/jsonb_plperl/sql/jsonb_plperlu.sql b/contrib/jsonb_plperl/sql/jsonb_plperlu.sql
index 9287f7672f..49c71fbc44 100644
--- a/contrib/jsonb_plperl/sql/jsonb_plperlu.sql
+++ b/contrib/jsonb_plperl/sql/jsonb_plperlu.sql
@@ -45,15 +45,21 @@ $$;
 SELECT testRegexpResultToJsonb();
 
 
-CREATE FUNCTION roundtrip(val jsonb) RETURNS jsonb
+CREATE FUNCTION roundtrip(val jsonb, ref text = '') RETURNS jsonb
 LANGUAGE plperlu
 TRANSFORM FOR TYPE jsonb
 AS $$
+use Data::Dumper;
+$Data::Dumper::Sortkeys = 1;
+$Data::Dumper::Indent = 0;
+elog(INFO, Dumper($_[0]));
+die 'unexpected '.(ref($_[0]) || 'not a').' reference'
+    if ref($_[0]) ne $_[1];
 return $_[0];
 $$;
 
 
-SELECT roundtrip('null');
+SELECT roundtrip('null') is null;
 SELECT roundtrip('1');
 SELECT roundtrip('1E+131071');
 SELECT roundtrip('-1');
@@ -65,23 +71,24 @@ SELECT roundtrip('"NaN"');
 SELECT roundtrip('true');
 SELECT roundtrip('false');
 
-SELECT roundtrip('[]');
-SELECT roundtrip('[null, null]');
-SELECT roundtrip('[1, 2, 3]');
-SELECT roundtrip('[-1, 2, -3]');
-SELECT roundtrip('[1.2, 2.3, 3.4]');
-SELECT roundtrip('[-1.2, 2.3, -3.4]');
-SELECT roundtrip('["string1", "string2"]');
+SELECT roundtrip('[]', 'ARRAY');
+SELECT roundtrip('[null, null]', 'ARRAY');
+SELECT roundtrip('[1, 2, 3]', 'ARRAY');
+SELECT roundtrip('[-1, 2, -3]', 'ARRAY');
+SELECT roundtrip('[1.2, 2.3, 3.4]', 'ARRAY');
+SELECT roundtrip('[-1.2, 2.3, -3.4]', 'ARRAY');
+SELECT roundtrip('["string1", "string2"]', 'ARRAY');
+SELECT roundtrip('[["string1", "string2"]]', 'ARRAY');
 
-SELECT roundtrip('{}');
-SELECT roundtrip('{"1": null}');
-SELECT roundtrip('{"1": 1}');
-SELECT roundtrip('{"1": -1}');
-SELECT roundtrip('{"1": 1.1}');
-SELECT roundtrip('{"1": -1.1}');
-SELECT roundtrip('{"1": "string1"}');
+SELECT roundtrip('{}', 'HASH');
+SELECT roundtrip('{"1": null}', 'HASH');
+SELECT roundtrip('{"1": 1}', 'HASH');
+SELECT roundtrip('{"1": -1}', 'HASH');
+SELECT roundtrip('{"1": 1.1}', 'HASH');
+SELECT roundtrip('{"1": -1.1}', 'HASH');
+SELECT roundtrip('{"1": "string1"}', 'HASH');
 
-SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}');
+SELECT roundtrip('{"1": {"2": [3, 4, 5]}, "2": 3}', 'HASH');
 
 
 \set VERBOSITY terse \\ -- suppress cascade details