*** a/contrib/auto_explain/auto_explain.c
--- b/contrib/auto_explain/auto_explain.c
***************
*** 290,299 **** explain_ExecutorEnd(QueryDesc *queryDesc)
  			es.buffers = (es.analyze && auto_explain_log_buffers);
  			es.format = auto_explain_log_format;
  
! 			ExplainBeginOutput(&es);
  			ExplainQueryText(&es, queryDesc);
  			ExplainPrintPlan(&es, queryDesc);
! 			ExplainEndOutput(&es);
  
  			/* Remove last line break */
  			if (es.str->len > 0 && es.str->data[es.str->len - 1] == '\n')
--- 290,299 ----
  			es.buffers = (es.analyze && auto_explain_log_buffers);
  			es.format = auto_explain_log_format;
  
! 			ExplainBeginLabeledOutput(&es);
  			ExplainQueryText(&es, queryDesc);
  			ExplainPrintPlan(&es, queryDesc);
! 			ExplainEndLabeledOutput(&es);
  
  			/* Remove last line break */
  			if (es.str->len > 0 && es.str->data[es.str->len - 1] == '\n')
*** a/src/backend/commands/explain.c
--- b/src/backend/commands/explain.c
***************
*** 2258,2263 **** ExplainEndOutput(ExplainState *es)
--- 2258,2302 ----
  }
  
  /*
+  * Emit the start-of-output boilerplate, if it's labeled, as auto_explain
+  * JSON is. For non-json cases, fall back on ExplainBeginOutput.
+  *
+  */
+ void
+ ExplainBeginLabeledOutput(ExplainState *es)
+ {
+ 	switch (es->format)
+ 	{
+ 		case EXPLAIN_FORMAT_JSON:
+ 			/* top level is an object of labeled items */
+ 			appendStringInfoChar(es->str, '{');
+ 			es->grouping_stack = lcons_int(0, es->grouping_stack);
+ 			es->indent++;
+ 			break;
+ 		default:
+ 			ExplainBeginOutput(es);
+ 	}
+ }
+ 
+ /* 
+  * Companion to ExplainBeginLabeledOutput
+  */
+ void
+ ExplainEndLabeledOutput(ExplainState *es)
+ {
+ 	switch (es->format)
+ 	{
+ 		case EXPLAIN_FORMAT_JSON:
+ 			es->indent--;
+ 			appendStringInfoString(es->str, "\n}");
+ 			es->grouping_stack = list_delete_first(es->grouping_stack);
+ 			break;
+ 		default:
+ 			ExplainEndOutput(es);
+ 	}
+ }
+ 
+ /*
   * Put an appropriate separator between multiple plans
   */
  void
*** a/src/include/commands/explain.h
--- b/src/include/commands/explain.h
***************
*** 71,76 **** extern void ExplainQueryText(ExplainState *es, QueryDesc *queryDesc);
--- 71,78 ----
  
  extern void ExplainBeginOutput(ExplainState *es);
  extern void ExplainEndOutput(ExplainState *es);
+ extern void ExplainBeginLabeledOutput(ExplainState *es);
+ extern void ExplainEndLabeledOutput(ExplainState *es);
  extern void ExplainSeparatePlans(ExplainState *es);
  
  extern void ExplainPropertyList(const char *qlabel, List *data,