diff --git a/composer.json b/composer.json
index 7c0da57..eaa698b 100644
--- a/composer.json
+++ b/composer.json
@@ -12,7 +12,7 @@
     ],
     "require": {
         "php": "^8.0",
-        "psr/clock": "^1.0"
+        "stella-maris/clock": "^0.1.6"
     },
     "require-dev": {
         "phpstan/extension-installer": "^1.2",
diff --git a/src/Clock.php b/src/Clock.php
index 5693d1d..02d9f71 100644
--- a/src/Clock.php
+++ b/src/Clock.php
@@ -4,7 +4,7 @@
 
 namespace Beste;
 
-use Psr\Clock\ClockInterface;
+use StellaMaris\Clock\ClockInterface;
 
 interface Clock extends ClockInterface
 {
diff --git a/src/Clock/FrozenClock.php b/src/Clock/FrozenClock.php
index 40f2895..f2bf651 100644
--- a/src/Clock/FrozenClock.php
+++ b/src/Clock/FrozenClock.php
@@ -7,7 +7,7 @@
 use Beste\Clock;
 use DateTimeImmutable;
 use DateTimeZone;
-use Psr\Clock\ClockInterface;
+use StellaMaris\Clock\ClockInterface;
 
 final class FrozenClock implements Clock
 {
diff --git a/src/Clock/MinuteClock.php b/src/Clock/MinuteClock.php
index 309545f..a7b5a31 100644
--- a/src/Clock/MinuteClock.php
+++ b/src/Clock/MinuteClock.php
@@ -6,7 +6,7 @@
 
 use Beste\Clock;
 use DateTimeImmutable;
-use Psr\Clock\ClockInterface;
+use StellaMaris\Clock\ClockInterface;
 
 final class MinuteClock implements Clock
 {
diff --git a/src/Clock/WrappingClock.php b/src/Clock/WrappingClock.php
index 80b1fd5..5919590 100644
--- a/src/Clock/WrappingClock.php
+++ b/src/Clock/WrappingClock.php
@@ -6,8 +6,7 @@
 
 use Beste\Clock;
 use DateTimeImmutable;
-use InvalidArgumentException;
-use Psr\Clock\ClockInterface;
+use StellaMaris\Clock\ClockInterface;
 
 final class WrappingClock implements Clock
 {
@@ -25,11 +24,11 @@ public static function wrapping(object $clock): self
         }
 
         if (!method_exists($clock, 'now')) {
-            throw new InvalidArgumentException('$clock must implement '.ClockInterface::class.' or have a now() method');
+            throw new \InvalidArgumentException('$clock must implement StellaMaris\Clock\ClockInterface or have a now() method');
         }
 
         if (!($clock->now() instanceof DateTimeImmutable)) {
-            throw new InvalidArgumentException('$clock->now() must return a DateTimeImmutable');
+            throw new \InvalidArgumentException('$clock->now() must return a DateTimeImmutable');
         }
 
         $wrappedClock = new class($clock) implements ClockInterface {
@@ -40,13 +39,13 @@ public function __construct(object $clock)
                 $this->clock = $clock;
             }
 
-            public function now(): DateTimeImmutable
+            public function now(): \DateTimeImmutable
             {
                 assert(method_exists($this->clock, 'now'));
 
                 $now = $this->clock->now();
 
-                assert($now instanceof DateTimeImmutable);
+                assert($now instanceof \DateTimeImmutable);
 
                 return $now;
             }
diff --git a/tests/Clock/FrozenClockTest.php b/tests/Clock/FrozenClockTest.php
index 42d5be8..af24b1a 100644
--- a/tests/Clock/FrozenClockTest.php
+++ b/tests/Clock/FrozenClockTest.php
@@ -7,7 +7,7 @@
 use Beste\Clock\FrozenClock;
 use DateTimeImmutable;
 use PHPUnit\Framework\TestCase;
-use Psr\Clock\ClockInterface;
+use StellaMaris\Clock\ClockInterface;
 
 /**
  * @internal
diff --git a/tests/Clock/MinuteClockTest.php b/tests/Clock/MinuteClockTest.php
index 729c0ac..baf55fb 100644
--- a/tests/Clock/MinuteClockTest.php
+++ b/tests/Clock/MinuteClockTest.php
@@ -7,7 +7,7 @@
 use Beste\Clock\MinuteClock;
 use DateTimeImmutable;
 use PHPUnit\Framework\TestCase;
-use Psr\Clock\ClockInterface;
+use StellaMaris\Clock\ClockInterface;
 
 /**
  * @internal