diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 411cfadbff..b67cc2f375 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -4233,6 +4233,9 @@ PostgresMain(int argc, char *argv[],
 				pgstat_report_activity(STATE_IDLE, NULL);
 			}
 
+			/* Report any recently-changed GUC options */
+			ReportChangedGUCOptions();
+
 			ReadyForQuery(whereToSendOutput);
 			send_ready_for_query = false;
 		}
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 596bcb7b84..ddfc7ea05d 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -4822,6 +4822,8 @@ static bool guc_dirty;			/* true if need to do commit/abort work */
 
 static bool reporting_enabled;	/* true to enable GUC_REPORT */
 
+static bool report_needed;		/* true if any GUC_REPORT reports are needed */
+
 static int	GUCNestLevel = 0;	/* 1 when in main transaction */
 
 
@@ -5828,7 +5830,10 @@ ResetAllOptions(void)
 		gconf->scontext = gconf->reset_scontext;
 
 		if (gconf->flags & GUC_REPORT)
-			ReportGUCOption(gconf);
+		{
+			gconf->status |= GUC_NEEDS_REPORT;
+			report_needed = true;
+		}
 	}
 }
 
@@ -6215,7 +6220,10 @@ AtEOXact_GUC(bool isCommit, int nestLevel)
 
 			/* Report new value if we changed it */
 			if (changed && (gconf->flags & GUC_REPORT))
-				ReportGUCOption(gconf);
+			{
+				gconf->status |= GUC_NEEDS_REPORT;
+				report_needed = true;
+			}
 		}						/* end of stack-popping loop */
 
 		if (stack != NULL)
@@ -6257,26 +6265,64 @@ BeginReportingGUCOptions(void)
 		if (conf->flags & GUC_REPORT)
 			ReportGUCOption(conf);
 	}
+
+	report_needed = false;
 }
 
 /*
- * ReportGUCOption: if appropriate, transmit option value to frontend
+ * Report recently-changed GUC_REPORT variables.
+ * This is called just before we wait for a new client query.
+ *
+ * By handling things this way, we ensure that a ParameterStatus message
+ * is sent at most once per variable per query, even if the variable
+ * changed multiple times within the query.  That's quite possible when
+ * using features such as function SET clauses.  We do not, however, go to
+ * the length of trying to suppress sending anything when the variable was
+ * changed and then reverted to its original value.
+ */
+void
+ReportChangedGUCOptions(void)
+{
+	/* Quick exit if not (yet) enabled */
+	if (!reporting_enabled)
+		return;
+
+	/* Quick exit if no values have been changed */
+	if (!report_needed)
+		return;
+
+	/* Transmit new values of interesting variables */
+	for (int i = 0; i < num_guc_variables; i++)
+	{
+		struct config_generic *conf = guc_variables[i];
+
+		if ((conf->flags & GUC_REPORT) && (conf->status & GUC_NEEDS_REPORT))
+			ReportGUCOption(conf);
+	}
+
+	report_needed = false;
+}
+
+/*
+ * ReportGUCOption: transmit option value to frontend
+ *
+ * Caller is now fully responsible for deciding whether this should be done.
+ * However, we do clear the NEEDS_REPORT flag here.
  */
 static void
 ReportGUCOption(struct config_generic *record)
 {
-	if (reporting_enabled && (record->flags & GUC_REPORT))
-	{
-		char	   *val = _ShowOption(record, false);
-		StringInfoData msgbuf;
+	char	   *val = _ShowOption(record, false);
+	StringInfoData msgbuf;
 
-		pq_beginmessage(&msgbuf, 'S');
-		pq_sendstring(&msgbuf, record->name);
-		pq_sendstring(&msgbuf, val);
-		pq_endmessage(&msgbuf);
+	pq_beginmessage(&msgbuf, 'S');
+	pq_sendstring(&msgbuf, record->name);
+	pq_sendstring(&msgbuf, val);
+	pq_endmessage(&msgbuf);
 
-		pfree(val);
-	}
+	pfree(val);
+
+	record->status &= ~GUC_NEEDS_REPORT;
 }
 
 /*
@@ -7667,7 +7713,10 @@ set_config_option(const char *name, const char *value,
 	}
 
 	if (changeVal && (record->flags & GUC_REPORT))
-		ReportGUCOption(record);
+	{
+		record->status |= GUC_NEEDS_REPORT;
+		report_needed = true;
+	}
 
 	return changeVal ? 1 : -1;
 }
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index 2819282181..76236fb0c0 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -362,6 +362,7 @@ extern void AtStart_GUC(void);
 extern int	NewGUCNestLevel(void);
 extern void AtEOXact_GUC(bool isCommit, int nestLevel);
 extern void BeginReportingGUCOptions(void);
+extern void ReportChangedGUCOptions(void);
 extern void ParseLongOption(const char *string, char **name, char **value);
 extern bool parse_int(const char *value, int *result, int flags,
 					  const char **hintmsg);
diff --git a/src/include/utils/guc_tables.h b/src/include/utils/guc_tables.h
index 04431d0eb2..a29c2b01b4 100644
--- a/src/include/utils/guc_tables.h
+++ b/src/include/utils/guc_tables.h
@@ -172,7 +172,8 @@ struct config_generic
  * Caution: the GUC_IS_IN_FILE bit is transient state for ProcessConfigFile.
  * Do not assume that its value represents useful information elsewhere.
  */
-#define GUC_PENDING_RESTART 0x0002
+#define GUC_PENDING_RESTART 0x0002	/* changed value cannot be applied yet */
+#define GUC_NEEDS_REPORT	0x0004	/* new value must be reported to client */
 
 
 /* GUC records for specific variable types */