diff --git a/packages/core/src/actions/index.ts b/packages/core/src/actions/index.ts
index c677cac9b..7b4e3fca9 100644
--- a/packages/core/src/actions/index.ts
+++ b/packages/core/src/actions/index.ts
@@ -26,8 +26,10 @@ import { RankedTester } from '../testers';
 import { JsonSchema, UISchemaElement } from '../';
 import { generateDefaultUISchema, generateJsonSchema } from '../generators';
 import { UISchemaTester } from '../reducers/uischemas';
+import * as AJV from 'ajv';
 
 export const INIT: 'jsonforms/INIT' = 'jsonforms/INIT';
+export const SET_AJV: 'jsonforms/SET_AJV' = 'jsonforms/SET_AJV';
 export const UPDATE_DATA: 'jsonforms/UPDATE' = 'jsonforms/UPDATE';
 export const VALIDATE: 'jsonforms/VALIDATE' = 'jsonforms/VALIDATE';
 export const ADD_RENDERER: 'jsonforms/ADD_RENDERER' = 'jsonforms/ADD_RENDERER';
@@ -50,13 +52,15 @@ export interface UpdateAction {
 export const init = (
   data: any,
   schema: JsonSchema = generateJsonSchema(data),
-  uischema: UISchemaElement = generateDefaultUISchema(schema)
+  uischema: UISchemaElement = generateDefaultUISchema(schema),
+  ajv?: AJV.Ajv
 ) =>
     ({
       type: INIT,
       data,
       schema,
-      uischema
+      uischema,
+      ajv
     });
 
 export const registerDefaultData = (
@@ -73,6 +77,13 @@ export const unregisterDefaultData = (schemaPath: string) => ({
     schemaPath
 });
 
+export const setAjv = (
+    ajv: AJV.Ajv
+) => ({
+    type: SET_AJV,
+    ajv
+});
+
 export const update =
   (path: string, updater: (any) => any): UpdateAction => ({
     type: UPDATE_DATA,
diff --git a/packages/core/src/reducers/core.ts b/packages/core/src/reducers/core.ts
index fa023a278..3772a05d5 100644
--- a/packages/core/src/reducers/core.ts
+++ b/packages/core/src/reducers/core.ts
@@ -24,7 +24,7 @@
 */
 import * as _ from 'lodash';
 import { ErrorObject, ValidateFunction } from 'ajv';
-import { INIT, UPDATE_DATA } from '../actions';
+import { INIT, SET_AJV, UPDATE_DATA } from '../actions';
 import { createAjv } from '../util/validator';
 import { JsonSchema, UISchemaElement } from '..';
 
@@ -70,7 +70,8 @@ export const coreReducer = (
   switch (action.type) {
     case INIT: {
 
-      const v = ajv.compile(action.schema);
+      const thisAjv = action.ajv ? action.ajv : ajv;
+      const v = thisAjv.compile(action.schema);
       const e = sanitizeErrors(v, action.data);
 
       return {
@@ -81,6 +82,16 @@ export const coreReducer = (
         errors: e
       };
     }
+    case SET_AJV: {
+      const currentAjv = action.ajv;
+      const validator = currentAjv.compile(state.schema);
+      const errors = sanitizeErrors(validator, state.data);
+      return {
+        ...state,
+        validator,
+        errors
+      };
+    }
     case UPDATE_DATA: {
 
       if (action.path === undefined || action.path === null) {