diff --git a/include/maxscale/query_classifier.h b/include/maxscale/query_classifier.h
index 6ce242303..f76b4dabf 100644
--- a/include/maxscale/query_classifier.h
+++ b/include/maxscale/query_classifier.h
@@ -121,6 +121,7 @@ typedef enum qc_query_op
     QUERY_OP_LOAD,
     QUERY_OP_REVOKE,
     QUERY_OP_SELECT,
+    QUERY_OP_SET,
     QUERY_OP_SHOW,
     QUERY_OP_TRUNCATE,
     QUERY_OP_UPDATE,
diff --git a/query_classifier/qc_mysqlembedded/qc_mysqlembedded.cc b/query_classifier/qc_mysqlembedded/qc_mysqlembedded.cc
index 019dc699f..001090196 100644
--- a/query_classifier/qc_mysqlembedded/qc_mysqlembedded.cc
+++ b/query_classifier/qc_mysqlembedded/qc_mysqlembedded.cc
@@ -2065,6 +2065,10 @@ int32_t qc_mysql_get_operation(GWBUF* querybuf, int32_t* operation)
                         *operation = QUERY_OP_REVOKE;
                         break;
 
+                    case SQLCOM_SET_OPTION:
+                        *operation = QUERY_OP_SET;
+                        break;
+
                     case SQLCOM_SHOW_CREATE:
                     case SQLCOM_SHOW_CREATE_DB:
                     case SQLCOM_SHOW_CREATE_FUNC:
diff --git a/query_classifier/qc_sqlite/qc_sqlite.cc b/query_classifier/qc_sqlite/qc_sqlite.cc
index 670628234..11cd1a4af 100644
--- a/query_classifier/qc_sqlite/qc_sqlite.cc
+++ b/query_classifier/qc_sqlite/qc_sqlite.cc
@@ -2651,6 +2651,7 @@ public:
             case TK_SET:
                 m_status = QC_QUERY_TOKENIZED;
                 m_type_mask = QUERY_TYPE_GSYSVAR_WRITE;
+                m_operation = QUERY_OP_SET;
                 break;
 
             case TK_SHOW:
@@ -2883,6 +2884,7 @@ public:
         mxb_assert(this_thread.initialized);
 
         m_status = QC_QUERY_PARSED;
+        m_operation = QUERY_OP_SET; // There will be no SET in case of Oracle's "var := 1".
         m_type_mask = 0;    // Reset what was set in maxscaleKeyword
 
         switch (kind)
diff --git a/query_classifier/test/maxscale.test b/query_classifier/test/maxscale.test
index 2a5758211..f757b164d 100644
--- a/query_classifier/test/maxscale.test
+++ b/query_classifier/test/maxscale.test
@@ -129,3 +129,6 @@ XA PREPARE 'xid';
 XA COMMIT 'xid';
 XA ROLLBACK 'xid'
 XA RECOVER 'xid';
+
+# MXS-2688
+SET @saved_cs_client= @@character_set_client;
diff --git a/server/core/query_classifier.cc b/server/core/query_classifier.cc
index 665d57d64..af682bc3b 100644
--- a/server/core/query_classifier.cc
+++ b/server/core/query_classifier.cc
@@ -855,6 +855,9 @@ const char* qc_op_to_string(qc_query_op_t op)
     case QUERY_OP_SELECT:
         return "QUERY_OP_SELECT";
 
+    case QUERY_OP_SET:
+        return "QUERY_OP_SET";
+
     case QUERY_OP_SHOW:
         return "QUERY_OP_SHOW";