diff --git a/dbms/src/Storages/AlterCommands.cpp b/dbms/src/Storages/AlterCommands.cpp
index b5fbe0f3314..2cde9562c82 100644
--- a/dbms/src/Storages/AlterCommands.cpp
+++ b/dbms/src/Storages/AlterCommands.cpp
@@ -8,6 +8,7 @@
 #include <Interpreters/ExpressionAnalyzer.h>
 #include <Interpreters/ExpressionActions.h>
 #include <Parsers/ASTIdentifier.h>
+#include <Parsers/ASTIndexDeclaration.h>
 #include <Parsers/ASTExpressionList.h>
 #include <Parsers/ASTLiteral.h>
 #include <Parsers/ASTFunction.h>
@@ -113,6 +114,36 @@ std::optional<AlterCommand> AlterCommand::parse(const ASTAlterCommand * command_
         command.order_by = command_ast->order_by;
         return command;
     }
+    else if (command_ast->type == ASTAlterCommand::ADD_INDEX)
+    {
+        AlterCommand command;
+        command.type = AlterCommand::ADD_INDEX;
+
+        const auto & ast_index_decl = typeid_cast<const ASTIndexDeclaration &>(*command_ast->index_decl);
+
+        command.index_name = ast_index_decl.name;
+
+        if (command_ast->index)
+            command.after_index_name = typeid_cast<const ASTIdentifier &>(*command_ast->index).name;
+
+        command.if_not_exists = command_ast->if_not_exists;
+
+        throw Exception("\"ALTER TABLE table ADD/DROP INDEX ...\" queries are not supported yet.", ErrorCodes::NOT_IMPLEMENTED);
+        return command;
+    }
+    else if (command_ast->type == ASTAlterCommand::DROP_INDEX)
+    {
+        if (command_ast->clear_column)
+            throw Exception("\"ALTER TABLE table CLEAR COLUMN column\" queries are not supported yet. Use \"CLEAR COLUMN column IN PARTITION\".", ErrorCodes::NOT_IMPLEMENTED);
+
+        AlterCommand command;
+        command.type = AlterCommand::DROP_INDEX;
+        command.index_name = typeid_cast<const ASTIdentifier &>(*(command_ast->index)).name;
+        command.if_exists = command_ast->if_exists;
+
+        throw Exception("\"ALTER TABLE table ADD/DROP INDEX ...\" queries are not supported yet.", ErrorCodes::NOT_IMPLEMENTED);
+        return command;
+    }
     else
         return {};
 }
diff --git a/dbms/src/Storages/AlterCommands.h b/dbms/src/Storages/AlterCommands.h
index c8d46dd5764..a465a8412ed 100644
--- a/dbms/src/Storages/AlterCommands.h
+++ b/dbms/src/Storages/AlterCommands.h
@@ -23,6 +23,8 @@ struct AlterCommand
         MODIFY_COLUMN,
         COMMENT_COLUMN,
         MODIFY_ORDER_BY,
+        ADD_INDEX,
+        DROP_INDEX,
         UKNOWN_TYPE,
     };
 
@@ -52,6 +54,13 @@ struct AlterCommand
     /// For MODIFY_ORDER_BY
     ASTPtr order_by;
 
+    /// For ADD INDEX
+    ASTPtr index_decl;
+    String after_index_name;
+
+    /// For ADD/DROP INDEX
+    String index_name;
+
     /// indicates that this command should not be applied, for example in case of if_exists=true and column doesn't exist.
     bool ignore = false;