diff --git a/tests/Console/E2ETest.php b/tests/Console/E2ETest.php
index fbe4aa2a6..039c36d89 100644
--- a/tests/Console/E2ETest.php
+++ b/tests/Console/E2ETest.php
@@ -216,7 +216,7 @@ private function installComposerDeps(): void
          */
 
         /*
-         * E2E tests are expected to follow PSR-4.
+         * E2E tests are expected to follow PSR-0 or PSR-4.
          *
          * We exploit this to autoload only classes belonging to the test,
          * but not to vendored deps (so we don't need them here, but to run
@@ -243,6 +243,19 @@ private function installComposerDeps(): void
             $loader->setPsr4($namespace, $paths);
         }
 
+        $mapPsr0 = require 'vendor/composer/autoload_namespaces.php';
+
+        foreach ($mapPsr0 as $namespace => $paths) {
+            foreach ($paths as $path) {
+                if (strpos($path, $vendorDir) !== false) {
+                    // Skip known dependency from autoloading
+                    continue 2;
+                }
+            }
+
+            $loader->set($namespace, $paths);
+        }
+
         $loader->register($prepend = false); // Note: not prepending, but appending to our autoloader
 
         $this->previousLoader = $loader;
diff --git a/tests/Fixtures/e2e/PSR_0_Autoloader/README.md b/tests/Fixtures/e2e/PSR_0_Autoloader/README.md
new file mode 100644
index 000000000..3c542ab48
--- /dev/null
+++ b/tests/Fixtures/e2e/PSR_0_Autoloader/README.md
@@ -0,0 +1,5 @@
+# PSR-0 test
+
+* Related to https://github.com/infection/infection/issues/564
+
+This test checks that Infection correctly works with PSR-0 compliant autoloader
diff --git a/tests/Fixtures/e2e/PSR_0_Autoloader/composer.json b/tests/Fixtures/e2e/PSR_0_Autoloader/composer.json
new file mode 100644
index 000000000..47a6ad56e
--- /dev/null
+++ b/tests/Fixtures/e2e/PSR_0_Autoloader/composer.json
@@ -0,0 +1,15 @@
+{
+    "require-dev": {
+        "phpunit/phpunit": "^6.5"
+    },
+    "autoload": {
+        "psr-0": {
+            "PSR_0_Autoloader": "src/"
+        }
+    },
+    "autoload-dev": {
+        "psr-0": {
+            "PSR_0_Autoloader\\Tests": "tests/"
+        }
+    }
+}
diff --git a/tests/Fixtures/e2e/PSR_0_Autoloader/expected-output.txt b/tests/Fixtures/e2e/PSR_0_Autoloader/expected-output.txt
new file mode 100644
index 000000000..99606b97d
--- /dev/null
+++ b/tests/Fixtures/e2e/PSR_0_Autoloader/expected-output.txt
@@ -0,0 +1,6 @@
+Total: 1
+Killed: 1
+Errored: 0
+Escaped: 0
+Timed Out: 0
+Not Covered: 0
\ No newline at end of file
diff --git a/tests/Fixtures/e2e/PSR_0_Autoloader/infection.json b/tests/Fixtures/e2e/PSR_0_Autoloader/infection.json
new file mode 100644
index 000000000..7029746fb
--- /dev/null
+++ b/tests/Fixtures/e2e/PSR_0_Autoloader/infection.json
@@ -0,0 +1,12 @@
+{
+    "timeout": 25,
+    "source": {
+        "directories": [
+            "src"
+        ]
+    },
+    "logs": {
+        "summary": "infection.log"
+    },
+    "tmpDir": "."
+}
diff --git a/tests/Fixtures/e2e/PSR_0_Autoloader/phpunit.xml b/tests/Fixtures/e2e/PSR_0_Autoloader/phpunit.xml
new file mode 100644
index 000000000..9a836774d
--- /dev/null
+++ b/tests/Fixtures/e2e/PSR_0_Autoloader/phpunit.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:noNamespaceSchemaLocation="./vendor/phpunit/phpunit/phpunit.xsd"
+         bootstrap="./vendor/autoload.php"
+         colors="true"
+>
+    <testsuites>
+        <testsuite name="Test Suite">
+            <directory>./tests/</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist>
+            <directory>./src/</directory>
+        </whitelist>
+    </filter>
+</phpunit>
diff --git a/tests/Fixtures/e2e/PSR_0_Autoloader/src/PSR_0_Autoloader/SourceClass.php b/tests/Fixtures/e2e/PSR_0_Autoloader/src/PSR_0_Autoloader/SourceClass.php
new file mode 100644
index 000000000..a97e5c55c
--- /dev/null
+++ b/tests/Fixtures/e2e/PSR_0_Autoloader/src/PSR_0_Autoloader/SourceClass.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace PSR_0_Autoloader;
+
+class SourceClass
+{
+    public function hello(): string
+    {
+        return 'hello';
+    }
+}
diff --git a/tests/Fixtures/e2e/PSR_0_Autoloader/tests/PSR_0_Autoloader/Tests/SourceClassTest.php b/tests/Fixtures/e2e/PSR_0_Autoloader/tests/PSR_0_Autoloader/Tests/SourceClassTest.php
new file mode 100644
index 000000000..40d8c906b
--- /dev/null
+++ b/tests/Fixtures/e2e/PSR_0_Autoloader/tests/PSR_0_Autoloader/Tests/SourceClassTest.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace PSR_0_Autoloader\Test;
+
+use PSR_0_Autoloader\SourceClass;
+use PHPUnit\Framework\TestCase;
+
+class SourceClassTest extends TestCase
+{
+    public function test_hello()
+    {
+        $sourceClass = new SourceClass();
+        $this->assertSame('hello', $sourceClass->hello());
+    }
+}