diff --git a/composer.json b/composer.json
index a4a5a10..3646ec5 100644
--- a/composer.json
+++ b/composer.json
@@ -54,7 +54,10 @@
     "autoload": {
         "psr-4": {
             "Craftzing\\TestBench\\": "src"
-        }
+        },
+        "files": [
+            "src/deprecated_aliases.php"
+        ]
     },
     "config": {
         "sort-packages": true
diff --git a/src/DeprecatedAliasesTest.php b/src/DeprecatedAliasesTest.php
new file mode 100644
index 0000000..68e5b6f
--- /dev/null
+++ b/src/DeprecatedAliasesTest.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Craftzing\TestBench;
+
+use Craftzing\TestBench\Doubles\Callable\CallableInvocation;
+use Craftzing\TestBench\Doubles\Callable\SpyCallable;
+use Craftzing\TestBench\Doubles\Enum\IntBackedEnum;
+use Craftzing\TestBench\Doubles\Enum\StringBackedEnum;
+use Craftzing\TestBench\Doubles\Enum\UnitEnum;
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\Attributes\TestWith;
+use PHPUnit\Framework\TestCase;
+use ReflectionClass;
+
+final class DeprecatedAliasesTest extends TestCase
+{
+    #[Test]
+    #[TestWith([CallableInvocation::class, 'Craftzing\TestBench\PHPUnit\Doubles\CallableInvocation'])]
+    #[TestWith([SpyCallable::class, 'Craftzing\TestBench\PHPUnit\Doubles\SpyCallable'])]
+    #[TestWith([StringBackedEnum::class, 'Craftzing\TestBench\PHPUnit\Doubles\Enums\StringBackedEnum'])]
+    #[TestWith([IntBackedEnum::class, 'Craftzing\TestBench\PHPUnit\Doubles\Enums\IntBackedEnum'])]
+    #[TestWith([UnitEnum::class, 'Craftzing\TestBench\PHPUnit\Doubles\Enums\UnitEnum'])]
+    public function itProvidesBackwardsCompatibilityThroughDeprecatedClassAliases(string $expected, string $alias): void
+    {
+        $actual = new ReflectionClass($alias)->getName();
+
+        $this->assertSame($expected, $actual);
+    }
+}
diff --git a/src/deprecated_aliases.php b/src/deprecated_aliases.php
new file mode 100644
index 0000000..8fa4318
--- /dev/null
+++ b/src/deprecated_aliases.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+use Craftzing\TestBench\Doubles\Callable\CallableInvocation;
+use Craftzing\TestBench\Doubles\Callable\SpyCallable;
+use Craftzing\TestBench\Doubles\Enum\IntBackedEnum;
+use Craftzing\TestBench\Doubles\Enum\StringBackedEnum;
+use Craftzing\TestBench\Doubles\Enum\UnitEnum;
+
+/**
+ * @deprecated since v1.2
+ * TODO v2: Remove these aliases in favour of the new FQCNs.
+ */
+class_alias(CallableInvocation::class, 'Craftzing\TestBench\PHPUnit\Doubles\CallableInvocation');
+class_alias(SpyCallable::class, 'Craftzing\TestBench\PHPUnit\Doubles\SpyCallable');
+class_alias(StringBackedEnum::class, 'Craftzing\TestBench\PHPUnit\Doubles\Enums\StringBackedEnum');
+class_alias(IntBackedEnum::class, 'Craftzing\TestBench\PHPUnit\Doubles\Enums\IntBackedEnum');
+class_alias(UnitEnum::class, 'Craftzing\TestBench\PHPUnit\Doubles\Enums\UnitEnum');