diff --git a/src/ng-select/items-list.spec.ts b/src/ng-select/items-list.spec.ts
index bd163ecb2..4f034e2f9 100644
--- a/src/ng-select/items-list.spec.ts
+++ b/src/ng-select/items-list.spec.ts
@@ -382,5 +382,5 @@ function itemsListFactory(cmp: NgSelectComponent): ItemsList {
 }
 
 function ngSelectFactory(): NgSelectComponent {
-    return new NgSelectComponent(null, null, {}, {} as any, null, null, null);
+    return new NgSelectComponent(null, null, {}, () => new DefaultSelectionModel(), {} as any, null, null);
 }
diff --git a/src/ng-select/ng-select.component.ts b/src/ng-select/ng-select.component.ts
index 97dc62240..6ddbb2f19 100644
--- a/src/ng-select/ng-select.component.ts
+++ b/src/ng-select/ng-select.component.ts
@@ -47,9 +47,10 @@ import { NgOption, KeyCode, NgSelectConfig } from './ng-select.types';
 import { newId } from './id';
 import { NgDropdownPanelComponent } from './ng-dropdown-panel.component';
 import { NgOptionComponent } from './ng-option.component';
-import { SelectionModel } from './selection-model';
+import { SelectionModelFactory } from './selection-model';
 
 export const NG_SELECT_DEFAULT_CONFIG = new InjectionToken<NgSelectConfig>('ng-select-default-options');
+export const SELECTION_MODEL_FACTORY = new InjectionToken<NgSelectConfig>('ng-select-selection-model');
 export type DropdownPosition = 'bottom' | 'top' | 'auto';
 export type AddTagFn = ((term: string) => any | Promise<any>);
 export type CompareWithFn = (a: any, b: any) => boolean;
@@ -175,14 +176,13 @@ export class NgSelectComponent implements OnDestroy, OnChanges, AfterViewInit, C
         @Attribute('class') public classes: string,
         @Attribute('tabindex') public tabIndex: string,
         @Inject(NG_SELECT_DEFAULT_CONFIG) config: NgSelectConfig,
+        @Inject(SELECTION_MODEL_FACTORY) newSelectionModel: SelectionModelFactory,
         _elementRef: ElementRef,
-        _selectionModel: SelectionModel,
         private _cd: ChangeDetectorRef,
-        private _console: ConsoleService,
-
+        private _console: ConsoleService
     ) {
         this._mergeGlobalConfig(config);
-        this.itemsList = new ItemsList(this, _selectionModel);
+        this.itemsList = new ItemsList(this, newSelectionModel());
         this.element = _elementRef.nativeElement;
     }
 
diff --git a/src/ng-select/ng-select.module.ts b/src/ng-select/ng-select.module.ts
index 40961d80a..63a630d1d 100644
--- a/src/ng-select/ng-select.module.ts
+++ b/src/ng-select/ng-select.module.ts
@@ -1,21 +1,22 @@
 import { NgModule } from '@angular/core';
 import { CommonModule } from '@angular/common';
-import { NgSelectComponent, NG_SELECT_DEFAULT_CONFIG } from './ng-select.component';
+import { NG_SELECT_DEFAULT_CONFIG, NgSelectComponent, SELECTION_MODEL_FACTORY } from './ng-select.component';
 import {
-    NgOptionTemplateDirective,
-    NgLabelTemplateDirective,
-    NgHeaderTemplateDirective,
     NgFooterTemplateDirective,
-    NgOptgroupTemplateDirective,
-    NgNotFoundTemplateDirective,
-    NgTypeToSearchTemplateDirective,
+    NgHeaderTemplateDirective,
+    NgLabelTemplateDirective,
     NgLoadingTextTemplateDirective,
     NgMultiLabelTemplateDirective,
-    NgTagTemplateDirective
+    NgNotFoundTemplateDirective,
+    NgOptgroupTemplateDirective,
+    NgOptionTemplateDirective,
+    NgTagTemplateDirective,
+    NgTypeToSearchTemplateDirective
 } from './ng-templates.directive';
 import { NgOptionComponent } from './ng-option.component';
-import { NgOptionHighlightDirective } from './ng-option-highlight.directive' ;
+import { NgOptionHighlightDirective } from './ng-option-highlight.directive';
 import { NgDropdownPanelComponent } from './ng-dropdown-panel.component';
+import { DefaultSelectionModel } from './selection-model';
 
 @NgModule({
     declarations: [
@@ -53,6 +54,7 @@ import { NgDropdownPanelComponent } from './ng-dropdown-panel.component';
         NgTagTemplateDirective
     ],
     providers: [
+        { provide: SELECTION_MODEL_FACTORY, useValue: () => new DefaultSelectionModel() },
         {
             provide: NG_SELECT_DEFAULT_CONFIG,
             useValue: {
diff --git a/src/ng-select/selection-model.ts b/src/ng-select/selection-model.ts
index 83eca0a6f..f6dd673f1 100644
--- a/src/ng-select/selection-model.ts
+++ b/src/ng-select/selection-model.ts
@@ -1,19 +1,15 @@
 import { NgOption } from './ng-select.types';
-import { Injectable } from '@angular/core';
 
-export function DEFAULT_SELECTION_MODEL_FACTORY() {
-    return new DefaultSelectionModel();
-}
+export type SelectionModelFactory = () => SelectionModel;
 
-@Injectable({ providedIn: 'root', useFactory: DEFAULT_SELECTION_MODEL_FACTORY })
-export abstract class SelectionModel {
-    abstract get value(): NgOption[];
-    abstract select(item: NgOption, multiple: boolean, selectableGroupAsModel: boolean);
-    abstract unselect(item: NgOption, multiple: boolean);
-    abstract clear();
+export interface SelectionModel {
+    value: NgOption[];
+    select(item: NgOption, multiple: boolean, selectableGroupAsModel: boolean);
+    unselect(item: NgOption, multiple: boolean);
+    clear();
 }
 
-export class DefaultSelectionModel {
+export class DefaultSelectionModel implements SelectionModel {
     private _selected: NgOption[] = [];
 
     get value(): NgOption[] {