diff --git a/packages/plugin-buidler/src/deploy-proxy.ts b/packages/plugin-buidler/src/deploy-proxy.ts
index bf3f8ea0d..e1c31e760 100644
--- a/packages/plugin-buidler/src/deploy-proxy.ts
+++ b/packages/plugin-buidler/src/deploy-proxy.ts
@@ -56,14 +56,16 @@ export function makeDeployProxy(bre: BuidlerRuntimeEnvironment): DeployFunction
     const allowNoInitialization = initializer === undefined && args.length === 0;
     initializer = initializer ?? 'initialize';
 
-    const initializers = ImplFactory.interface.fragments.filter(f => f.name === initializer);
-
-    if (initializers.length > 0) {
-      return ImplFactory.interface.encodeFunctionData(initializer, args);
-    } else if (allowNoInitialization) {
-      return '0x';
-    } else {
-      throw new Error(`Contract does not have a function \`${initializer}\``);
+    try {
+      const fragment = ImplFactory.interface.getFunction(initializer);
+      return ImplFactory.interface.encodeFunctionData(fragment, args);
+    } catch (e: unknown) {
+      if (e instanceof Error) {
+        if (allowNoInitialization && e.message.includes('no matching function')) {
+          return '0x';
+        }
+      }
+      throw e;
     }
   }
 }
diff --git a/packages/plugin-buidler/test.js b/packages/plugin-buidler/test.js
index 3841ca2bb..708db7767 100644
--- a/packages/plugin-buidler/test.js
+++ b/packages/plugin-buidler/test.js
@@ -40,3 +40,4 @@ testFile('deploy-validation');
 testFile('upgrade-validation');
 testFile('upgrade-storage');
 testFile('admin-validation');
+testFile('initializers');
diff --git a/packages/plugin-buidler/test/contracts/Initializers.sol b/packages/plugin-buidler/test/contracts/Initializers.sol
new file mode 100644
index 000000000..f44973844
--- /dev/null
+++ b/packages/plugin-buidler/test/contracts/Initializers.sol
@@ -0,0 +1,14 @@
+pragma solidity ^0.5.1;
+
+contract InitializerOverloaded {
+  uint public x;
+
+  function initialize(uint _x) public {
+    x = _x;
+  }
+
+  function initialize(string memory) public {}
+}
+
+contract InitializerMissing {
+}
diff --git a/packages/plugin-buidler/test/initializers.js b/packages/plugin-buidler/test/initializers.js
new file mode 100644
index 000000000..a2a4f49af
--- /dev/null
+++ b/packages/plugin-buidler/test/initializers.js
@@ -0,0 +1,18 @@
+const assert = require('assert');
+const { ethers, upgrades } = require('@nomiclabs/buidler');
+
+async function main() {
+  const InitializerOverloaded = await ethers.getContractFactory('InitializerOverloaded');
+  const instance = await upgrades.deployProxy(InitializerOverloaded, [42], { initializer: 'initialize(uint256)' });
+  assert.strictEqual('42', (await instance.x()).toString());
+
+  const InitializerMissing = await ethers.getContractFactory('InitializerMissing');
+  await upgrades.deployProxy(InitializerMissing);
+}
+
+main()
+  .then(() => process.exit(0))
+  .catch(error => {
+    console.error(error);
+    process.exit(1);
+  });