diff --git a/include/maxscale/protocol/mysql.h b/include/maxscale/protocol/mysql.h
index b97c30883..67837451e 100644
--- a/include/maxscale/protocol/mysql.h
+++ b/include/maxscale/protocol/mysql.h
@@ -307,6 +307,7 @@ typedef enum
     MXS_COM_STMT_RESET = 26,
     MXS_COM_SET_OPTION = 27,
     MXS_COM_STMT_FETCH = 28,
+    MXS_COM_STMT_BULK_EXECUTE = 0xfa,
     MXS_COM_DAEMON,
     MXS_COM_END
 } mxs_mysql_cmd_t;
diff --git a/maxscale-system-test/CMakeLists.txt b/maxscale-system-test/CMakeLists.txt
index e3515b754..047589f63 100644
--- a/maxscale-system-test/CMakeLists.txt
+++ b/maxscale-system-test/CMakeLists.txt
@@ -703,6 +703,10 @@ add_test_executable(mxs1828_double_local_infile.cpp mxs1828_double_local_infile
 # https://jira.mariadb.org/browse/MXS-1831
 add_test_executable(mxs1831_unknown_param.cpp mxs1831_unknown_param replication LABELS REPL_BACKEND)
 
+# MXS-1873: Large session commands cause errors
+# https://jira.mariadb.org/browse/MXS-1873
+add_test_executable(mxs1873_large_sescmd.cpp mxs1873_large_sescmd replication LABELS readwritesplit REPL_BACKEND)
+
 # 'namedserverfilter' test
 add_test_executable(namedserverfilter.cpp namedserverfilter namedserverfilter LABELS namedserverfilter LIGHT REPL_BACKEND)
 
diff --git a/maxscale-system-test/mxs1873_large_sescmd.cpp b/maxscale-system-test/mxs1873_large_sescmd.cpp
new file mode 100644
index 000000000..bd6285919
--- /dev/null
+++ b/maxscale-system-test/mxs1873_large_sescmd.cpp
@@ -0,0 +1,20 @@
+/**
+ * MXS-1873: Large session commands cause errors
+ *
+ * https://jira.mariadb.org/browse/MXS-1873
+ */
+
+#include "testconnections.h"
+
+int main(int argc, char** argv)
+{
+    TestConnections test(argc, argv);
+
+    test.maxscales->connect();
+    test.try_query(test.maxscales->conn_rwsplit[0],
+                   "SET STATEMENT max_statement_time=30 FOR SELECT seq FROM seq_0_to_100000");
+    test.try_query(test.maxscales->conn_rwsplit[0], "SELECT 1");
+    test.maxscales->disconnect();
+
+    return test.global_result;
+}
diff --git a/server/core/queryclassifier.cc b/server/core/queryclassifier.cc
index 7480df86d..89a3c1ae3 100644
--- a/server/core/queryclassifier.cc
+++ b/server/core/queryclassifier.cc
@@ -38,6 +38,7 @@ const char* qc_mysql_get_current_db(MXS_SESSION* session)
 bool qc_mysql_is_ps_command(uint8_t cmd)
 {
     return cmd == MXS_COM_STMT_EXECUTE ||
+           cmd == MXS_COM_STMT_BULK_EXECUTE ||
            cmd == MXS_COM_STMT_SEND_LONG_DATA ||
            cmd == MXS_COM_STMT_CLOSE ||
            cmd == MXS_COM_STMT_FETCH ||
diff --git a/server/modules/protocol/MySQL/mysql_common.cc b/server/modules/protocol/MySQL/mysql_common.cc
index 8abe07763..01560c915 100644
--- a/server/modules/protocol/MySQL/mysql_common.cc
+++ b/server/modules/protocol/MySQL/mysql_common.cc
@@ -1606,6 +1606,7 @@ bool mxs_mysql_is_prep_stmt_ok(GWBUF *buffer)
 bool mxs_mysql_is_ps_command(uint8_t cmd)
 {
     return cmd == MXS_COM_STMT_EXECUTE ||
+           cmd == MXS_COM_STMT_BULK_EXECUTE ||
            cmd == MXS_COM_STMT_SEND_LONG_DATA ||
            cmd == MXS_COM_STMT_CLOSE ||
            cmd == MXS_COM_STMT_FETCH ||
diff --git a/server/modules/routing/readwritesplit/rwsplit_route_stmt.cc b/server/modules/routing/readwritesplit/rwsplit_route_stmt.cc
index 1718eae2b..e88d32e0c 100644
--- a/server/modules/routing/readwritesplit/rwsplit_route_stmt.cc
+++ b/server/modules/routing/readwritesplit/rwsplit_route_stmt.cc
@@ -349,11 +349,11 @@ bool RWSplitSession::route_session_write(GWBUF *querybuf, uint8_t command, uint3
     bool expecting_response = mxs_mysql_command_will_respond(command);
     int nsucc = 0;
     uint64_t lowest_pos = id;
+    gwbuf_set_type(querybuf, GWBUF_TYPE_COLLECT_RESULT);
 
     if (qc_query_is_type(type, QUERY_TYPE_PREPARE_NAMED_STMT) ||
         qc_query_is_type(type, QUERY_TYPE_PREPARE_STMT))
     {
-        gwbuf_set_type(querybuf, GWBUF_TYPE_COLLECT_RESULT);
         m_qc.ps_store(querybuf, id);
     }