diff --git a/doc/src/sgml/parallel.sgml b/doc/src/sgml/parallel.sgml
index f39c21a4550..cf4c1c9c2a9 100644
--- a/doc/src/sgml/parallel.sgml
+++ b/doc/src/sgml/parallel.sgml
@@ -227,6 +227,15 @@ EXPLAIN SELECT * FROM pgbench_accounts WHERE filler LIKE '%x%';
       </para>
     </listitem>
 
+    <listitem>
+      <para> 
+        A prepared statement is executed using a <literal>CREATE TABLE .. AS
+        EXECUTE ..</literal> statement.  This construct converts what otherwise
+        would have been a read-only operation into a read-write operation,
+        making it ineligible for parallel query.
+      </para>
+    </listitem>
+
     <listitem>
       <para> 
         The transaction isolation level is serializable.  This situation
diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index cec37ce0405..b01051df9d2 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -159,7 +159,7 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
 					   nargs,
 					   NULL,
 					   NULL,
-					   0,		/* default cursor options */
+					   CURSOR_OPT_PARALLEL_OK,	/* allow parallel mode */
 					   true);	/* fixed result */
 
 	/*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index 32bb3f92054..71c07288a19 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -1540,10 +1540,11 @@ ExecutePlan(EState *estate,
 	estate->es_direction = direction;
 
 	/*
-	 * If a tuple count was supplied, we must force the plan to run without
-	 * parallelism, because we might exit early.
+	 * If a tuple count was supplied or data is being written to relation, we
+	 * must force the plan to run without parallelism, because we might exit
+	 * early.
 	 */
-	if (numberTuples)
+	if (numberTuples || dest->mydest == DestIntoRel)
 		use_parallel_mode = false;
 
 	/*