diff --git a/packages/core/package.json b/packages/core/package.json
index 8445c8d0b..284041bba 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -16,6 +16,7 @@
     "prepublish": "rimraf artifacts cache dist *.tsbuildinfo",
     "prepare": "tsc -b && yarn prepare:contracts",
     "prepare:contracts": "hardhat compile",
+    "prepublishOnly": "bash scripts/copy-artifacts.sh",
     "test": "tsc -b && hardhat compile --force && ava",
     "test:watch": "hardhat compile --force && fgbg 'ava --watch' 'tsc -b --watch'",
     "version": "node ../../scripts/bump-changelog.js"
diff --git a/packages/core/scripts/copy-artifacts.sh b/packages/core/scripts/copy-artifacts.sh
new file mode 100644
index 000000000..7007bdff6
--- /dev/null
+++ b/packages/core/scripts/copy-artifacts.sh
@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+# copies proxy artifacts to the location they were until 1.3.0 for backwards compatibility with truffle plugin
+
+cp artifacts/contracts/proxy/{AdminUpgradeabilityProxy.sol/AdminUpgradeabilityProxy.json,ProxyAdmin.sol/ProxyAdmin.json} artifacts
diff --git a/packages/core/src/validate.test.ts b/packages/core/src/validate.test.ts
index 7df597048..c7a94c5ff 100644
--- a/packages/core/src/validate.test.ts
+++ b/packages/core/src/validate.test.ts
@@ -8,12 +8,12 @@ import {
   getContractVersion,
   assertUpgradeSafe,
   ValidationOptions,
-  ValidationLog,
+  RunValidation,
 } from './validate';
 import { solcInputOutputDecoder } from './src-decoder';
 
 interface Context {
-  validations: ValidationLog;
+  validation: RunValidation;
 }
 
 const test = _test as TestInterface<Context>;
@@ -26,21 +26,21 @@ test.before(async t => {
   const solcOutput = buildInfo.output;
   const solcInput = buildInfo.input;
   const decodeSrc = solcInputOutputDecoder(solcInput, solcOutput);
-  t.context.validations = [validate(solcOutput, decodeSrc)];
+  t.context.validation = validate(solcOutput, decodeSrc);
 });
 
 function testValid(name: string, valid: boolean) {
   test(name, t => {
-    const version = getContractVersion(t.context.validations, name, 0);
-    t.is(isUpgradeSafe(t.context.validations, version), valid);
+    const version = getContractVersion(t.context.validation, name);
+    t.is(isUpgradeSafe([t.context.validation], version), valid);
   });
 }
 
 function testOverride(name: string, opts: ValidationOptions, valid: boolean) {
   const testName = name.concat(valid ? '_Allowed' : '_NotAllowed');
   test(testName, t => {
-    const version = getContractVersion(t.context.validations, name, 0);
-    const assertUpgSafe = () => assertUpgradeSafe(t.context.validations, version, opts);
+    const version = getContractVersion(t.context.validation, name);
+    const assertUpgSafe = () => assertUpgradeSafe([t.context.validation], version, opts);
     if (valid) {
       t.notThrows(assertUpgSafe);
     } else {
@@ -83,8 +83,8 @@ testValid('ParentHasEnum', false);
 testValid('UsesLibraryWithEnum', false);
 
 test('inherited storage', t => {
-  const version = getContractVersion(t.context.validations, 'StorageInheritChild', 0);
-  const layout = getStorageLayout(t.context.validations, version);
+  const version = getContractVersion(t.context.validation, 'StorageInheritChild');
+  const layout = getStorageLayout([t.context.validation], version);
   t.is(layout.storage.length, 8);
   for (let i = 0; i < layout.storage.length; i++) {
     t.is(layout.storage[i].label, `v${i}`);
diff --git a/packages/core/src/validate.ts b/packages/core/src/validate.ts
index c599a989c..826a73f37 100644
--- a/packages/core/src/validate.ts
+++ b/packages/core/src/validate.ts
@@ -13,6 +13,14 @@ import { isNullish } from './utils/is-nullish';
 export type ValidationLog = RunValidation[];
 export type RunValidation = Record<string, ContractValidation>;
 
+// upgrades-core@1.3.0 introduced ValidationLog but for compatibility with ^1.0.0
+// the functions exported by this module also accept a single RunValidation
+type Validations = ValidationLog | RunValidation;
+
+// aliases for backwards compatibility with ^1.0.0
+export type Validation = RunValidation;
+export type ValidationResult = ContractValidation;
+
 export interface ContractValidation {
   version?: Version;
   inherit: string[];
@@ -121,19 +129,21 @@ export function validate(solcOutput: SolcOutput, decodeSrc: SrcDecoder): RunVali
   return validation;
 }
 
-export function getContractVersion(validations: ValidationLog, contractName: string, compilationRun: number): Version {
-  const { version } = validations[compilationRun][contractName];
+export function getContractVersion(validation: RunValidation, contractName: string): Version {
+  const { version } = validation[contractName];
   if (version === undefined) {
     throw new Error(`Contract ${contractName} is abstract`);
   }
   return version;
 }
 
-export function getContractNameAndRunValidation(validations: ValidationLog, version: Version): [string, RunValidation] {
+export function getContractNameAndRunValidation(validations: Validations, version: Version): [string, RunValidation] {
+  const validationLog = Array.isArray(validations) ? validations : [validations];
+
   let runValidation;
   let contractName;
 
-  for (const validation of validations) {
+  for (const validation of validationLog) {
     contractName = Object.keys(validation).find(
       name => validation[name].version?.withMetadata === version.withMetadata,
     );
@@ -150,7 +160,7 @@ export function getContractNameAndRunValidation(validations: ValidationLog, vers
   return [contractName, runValidation];
 }
 
-export function getStorageLayout(validations: ValidationLog, version: Version): StorageLayout {
+export function getStorageLayout(validations: Validations, version: Version): StorageLayout {
   const [contractName, runValidation] = getContractNameAndRunValidation(validations, version);
   const c = runValidation[contractName];
   const layout: StorageLayout = { storage: [], types: {} };
@@ -161,8 +171,10 @@ export function getStorageLayout(validations: ValidationLog, version: Version):
   return layout;
 }
 
-export function getUnlinkedBytecode(validations: ValidationLog, bytecode: string): string {
-  for (const validation of validations) {
+export function getUnlinkedBytecode(validations: Validations, bytecode: string): string {
+  const validationLog = Array.isArray(validations) ? validations : [validations];
+
+  for (const validation of validationLog) {
     const linkableContracts = Object.keys(validation).filter(name => validation[name].linkReferences.length > 0);
 
     for (const name of linkableContracts) {
@@ -179,7 +191,7 @@ export function getUnlinkedBytecode(validations: ValidationLog, bytecode: string
   return bytecode;
 }
 
-export function assertUpgradeSafe(validations: ValidationLog, version: Version, opts: ValidationOptions): void {
+export function assertUpgradeSafe(validations: Validations, version: Version, opts: ValidationOptions): void {
   const [contractName] = getContractNameAndRunValidation(validations, version);
 
   let errors = getErrors(validations, version);
@@ -314,7 +326,7 @@ function describeError(e: ValidationError): string {
   return log.join('\n    ');
 }
 
-export function getErrors(validations: ValidationLog, version: Version): ValidationError[] {
+export function getErrors(validations: Validations, version: Version): ValidationError[] {
   const [contractName, runValidation] = getContractNameAndRunValidation(validations, version);
   const c = runValidation[contractName];
   return c.errors
@@ -322,7 +334,7 @@ export function getErrors(validations: ValidationLog, version: Version): Validat
     .concat(...c.libraries.map(name => runValidation[name].errors));
 }
 
-export function isUpgradeSafe(validations: ValidationLog, version: Version): boolean {
+export function isUpgradeSafe(validations: Validations, version: Version): boolean {
   return getErrors(validations, version).length == 0;
 }