diff --git a/src/interfaces/libpq/fe-exec.c b/src/interfaces/libpq/fe-exec.c
index 78cff4475c..1b9c04f47e 100644
--- a/src/interfaces/libpq/fe-exec.c
+++ b/src/interfaces/libpq/fe-exec.c
@@ -1196,6 +1196,7 @@ pqSaveParameterStatus(PGconn *conn, const char *name, const char *value)
  *	  Returns 1 if OK, 0 if error occurred.
  *
  * On error, *errmsgp can be set to an error string to be returned.
+ * (Such a string should already be translated via libpq_gettext().)
  * If it is left NULL, the error is presumed to be "out of memory".
  *
  * In single-row mode, we create a new result holding just the current row,
diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index 94b4a448b9..e0da22dba7 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -209,7 +209,7 @@ pqParseInput3(PGconn *conn)
 				case 'C':		/* command complete */
 					if (pqGets(&conn->workBuffer, conn))
 						return;
-					if (conn->result == NULL)
+					if (conn->result == NULL && !conn->error_result)
 					{
 						conn->result = PQmakeEmptyPGresult(conn,
 														   PGRES_COMMAND_OK);
@@ -263,7 +263,7 @@ pqParseInput3(PGconn *conn)
 					}
 					break;
 				case 'I':		/* empty query */
-					if (conn->result == NULL)
+					if (conn->result == NULL && !conn->error_result)
 					{
 						conn->result = PQmakeEmptyPGresult(conn,
 														   PGRES_EMPTY_QUERY);
@@ -281,7 +281,7 @@ pqParseInput3(PGconn *conn)
 					if (conn->cmd_queue_head &&
 						conn->cmd_queue_head->queryclass == PGQUERY_PREPARE)
 					{
-						if (conn->result == NULL)
+						if (conn->result == NULL && !conn->error_result)
 						{
 							conn->result = PQmakeEmptyPGresult(conn,
 															   PGRES_COMMAND_OK);
@@ -362,7 +362,7 @@ pqParseInput3(PGconn *conn)
 					if (conn->cmd_queue_head &&
 						conn->cmd_queue_head->queryclass == PGQUERY_DESCRIBE)
 					{
-						if (conn->result == NULL)
+						if (conn->result == NULL && !conn->error_result)
 						{
 							conn->result = PQmakeEmptyPGresult(conn,
 															   PGRES_COMMAND_OK);