diff --git a/src/to-vue-2.js b/src/to-vue-2.js
index 4e46573..f8c8294 100644
--- a/src/to-vue-2.js
+++ b/src/to-vue-2.js
@@ -1,8 +1,16 @@
-import Vue from 'vue';
 import frag from 'vue-frag';
-import {createApp, h} from 'vue3';
 import {vue3ProxyNode} from './utils';
 
+let Vue2;
+try {
+	Vue2 = require('vue');
+} catch {}
+
+let Vue3;
+try {
+	Vue3 = require('vue3');
+} catch {}
+
 const camelizeRE = /-(\w)/g;
 
 function normalizeEventName(eventName) {
@@ -53,7 +61,7 @@ const renderVue2Vnode = /* Vue 3 component */ {
 
 	mounted() {
 		const vm = this;
-		this.vue2App = (new Vue({
+		this.vue2App = (new Vue2({
 			beforeCreate() {
 				this.$parent = vm.parent;
 			},
@@ -82,14 +90,14 @@ const renderVue2Vnode = /* Vue 3 component */ {
 			this.vue2App.$forceUpdate();
 		}
 
-		return h('div');
+		return Vue3.h('div');
 	},
 };
 
 function interopSlots(ctx) {
 	const scopedSlots = {};
 	for (const slotName in ctx.$scopedSlots) {
-		scopedSlots[slotName] = () => h(renderVue2Vnode, {
+		scopedSlots[slotName] = () => Vue3.h(renderVue2Vnode, {
 			parent: ctx,
 			vnode: ctx.$scopedSlots[slotName],
 		});
@@ -127,8 +135,8 @@ const vue2WrapperBase = {
 	// Delay until mounted for SSR
 	mounted() {
 		const vm = this;
-		this.v3app = createApp({
-			render: () => h(
+		this.v3app = Vue3.createApp({
+			render: () => Vue3.h(
 				this.$options.component,
 				mergeAttrsListeners(this),
 				interopSlots(this),
@@ -171,9 +179,32 @@ const vue2WrapperBase = {
 };
 
 const toVue2 = vue3Component => {
+	if (!Vue2 && !Vue3) {
+		throw new Error('Vue 2 & 3 were not resolved with bare specifiers "vue" & "vue3". Register them with toVue3.register(Vue2, Vue3)');
+	}
+
+	if (!Vue2) {
+		throw new Error('Vue 2 was not resolved with bare specifier "vue". Register it with toVue3.register(Vue)');
+	}
+
+	if (!Vue3) {
+		throw new Error('Vue 3 was not resolved with bare specifier "vue3". Register it with toVue3.register(Vue3) or toVue3.register({ createApp, h })');
+	}
+
 	const vue2Wrapper = Object.create(vue2WrapperBase);
 	vue2Wrapper.component = vue3Component;
 	return vue2Wrapper;
 };
 
+toVue2.register = function () {
+	for (let i = 0; i < arguments.length; i += 1) { // eslint-disable-line unicorn/no-for-loop
+		const Vue = arguments[i];
+		if (typeof Vue === 'function' && Vue.version && Vue.version.startsWith('2')) {
+			Vue2 = Vue;
+		} else if (Vue.createApp && Vue.h) {
+			Vue3 = Vue;
+		}
+	}
+};
+
 export default toVue2;
diff --git a/src/to-vue-3.js b/src/to-vue-3.js
index 08e7021..4263234 100644
--- a/src/to-vue-3.js
+++ b/src/to-vue-3.js
@@ -1,7 +1,15 @@
-import Vue from 'vue';
-import {createApp, h} from 'vue3';
 import {vue3ProxyNode} from './utils';
 
+let Vue2;
+try {
+	// Vue2 = require('vue');
+} catch {}
+
+let Vue3;
+try {
+	// Vue3 = require('vue3');
+} catch {}
+
 const hyphenateRE = /\B([A-Z])/g;
 const hyphenate = string => string.replace(hyphenateRE, '-$1').toLowerCase();
 
@@ -54,7 +62,7 @@ const renderVue3Vnode = {
 	props: ['parent', 'vnode'],
 
 	mounted() {
-		this.vue3App = createApp({
+		this.vue3App = Vue3.createApp({
 			render: () => this.vnode(),
 		});
 
@@ -112,7 +120,7 @@ const vue3WrapperBase = {
 		const vm = this;
 		const mountElement = this.$el;
 
-		this.v2 = new Vue({
+		this.v2 = new Vue2({
 			provide() {
 				return new Proxy(vm._.provides, {
 					getOwnPropertyDescriptor(target, key) {
@@ -170,7 +178,7 @@ const vue3WrapperBase = {
 			this.v2.$forceUpdate();
 		}
 
-		return h('div');
+		return Vue3.h('div');
 	},
 };
 
@@ -181,6 +189,18 @@ const getProvidedMixin = {
 };
 
 const toVue3 = vue2Component => {
+	if (!Vue2 && !Vue3) {
+		throw new Error('Vue 2 & 3 were not resolved with bare specifiers "vue" & "vue3". Register them with toVue3.register(Vue2, Vue3)');
+	}
+
+	if (!Vue2) {
+		throw new Error('Vue 2 was not resolved with bare specifier "vue". Register it with toVue3.register(Vue)');
+	}
+
+	if (!Vue3) {
+		throw new Error('Vue 3 was not resolved with bare specifier "vue3". Register it with toVue3.register(Vue3) or toVue3.register({ createApp, h })');
+	}
+
 	const component = Object.create(vue2Component);
 	component.mixins = [getProvidedMixin].concat(vue2Component.mixins || []);
 
@@ -190,4 +210,15 @@ const toVue3 = vue2Component => {
 	return vue3Wrapper;
 };
 
+toVue3.register = function () {
+	for (let i = 0; i < arguments.length; i += 1) { // eslint-disable-line unicorn/no-for-loop
+		const Vue = arguments[i];
+		if (typeof Vue === 'function' && Vue.version && Vue.version.startsWith('2')) {
+			Vue2 = Vue;
+		} else if (Vue.createApp && Vue.h) {
+			Vue3 = Vue;
+		}
+	}
+};
+
 export default toVue3;
diff --git a/test/to-vue-2.spec.js b/test/to-vue-2.spec.js
index 358b542..9d950db 100644
--- a/test/to-vue-2.spec.js
+++ b/test/to-vue-2.spec.js
@@ -1,6 +1,10 @@
 const {default: toVue2} = require('vue-2-3/to-vue-2');
-const {createApp, provide, inject, nextTick} = require('vue3');
+const Vue = require('vue');
+const Vue3 = require('vue3');
 const {mount} = require('@vue/test-utils');
+const {createApp, provide, inject, nextTick} = Vue3;
+
+toVue2.register(Vue, Vue3);
 
 describe('Error handling', () => {
 	test('throw error when used in vue 3 app', () => {
diff --git a/test/to-vue-3.spec.js b/test/to-vue-3.spec.js
index dadcfba..907e9c3 100644
--- a/test/to-vue-3.spec.js
+++ b/test/to-vue-3.spec.js
@@ -1,8 +1,12 @@
 const {default: toVue3} = require('vue-2-3/to-vue-3');
-const {createApp, nextTick} = require('vue3');
+const Vue3 = require('vue3');
 const outdent = require('outdent');
 const Vue = require('vue');
 
+const {createApp, nextTick} = Vue3;
+
+toVue3.register(Vue, Vue3);
+
 let mountTarget;
 let app;
 beforeEach(() => {