MDB-Select Input small

I'm trying to size Input of MDB-Select with class form-control-sm, but that don't affect Input component and break MDB-Select.

My HTML code:

                <mdb-form-control>
                    <mdb-select [(ngModel)]="filterObj.length" (valueChange)="filterModul($event)">
                        <mdb-option [value]="5">5</mdb-option>
                        <mdb-option [value]="10">10</mdb-option>
                        <mdb-option [value]="15">15</mdb-option>
                    </mdb-select>
                    <label mdbLabel class="form-label">Enteries</label>
                </mdb-form-control>

Inspect element give me this code:

<mdb-select _ngcontent-ng-c3157040990="" class="ng-tns-c1912133661-6 select d-block ng-valid ng-star-inserted active ng-touched ng-dirty" ng-reflect-model="10" aria-multiselectable="false" aria-haspopup="true" aria-disabled="false" aria-expanded="false" aria-role="listbox">

<input mdbinput="" type="text" readonly="" class="form-control select-input ng-tns-c1912133661-6 active"
    placeholder="">
<!--bindings={
  "ng-reflect-ng-if": "false"
}-->

<span class="select-arrow ng-tns-c1912133661-6"></span>
<!--container-->

Enteries

When I edit Input in browser inspect window to this

<input mdbinput="" type="text" readonly="" class="form-control form-control-sm select-input ng-tns-c1912133661-6 active" placeholder="">

I got nice select:

My question is how to size Input od MDB-Select with form-control-sm class?