diff --git a/src/Behavior/MillisecondTimestamp.php b/src/Behavior/MillisecondTimestamp.php
index 76b818b..f23a89c 100644
--- a/src/Behavior/MillisecondTimestamp.php
+++ b/src/Behavior/MillisecondTimestamp.php
@@ -12,8 +12,8 @@ class MillisecondTimestamp extends PropertyBehavior
 {
     public function fromDb($value, $key, $context)
     {
-        if ($value === null) {
-            return null;
+        if ($value === null || $value instanceof DateTime) {
+            return $value;
         }
 
         $datetime = DateTime::createFromFormat('U.u', sprintf('%F', $value / 1000.0));
diff --git a/src/Behavior/UUID.php b/src/Behavior/UUID.php
index 85072e1..3bc93c9 100644
--- a/src/Behavior/UUID.php
+++ b/src/Behavior/UUID.php
@@ -20,8 +20,8 @@ class UUID extends PropertyBehavior implements QueryAwareBehavior
 
     public function fromDb($value, $key, $_)
     {
-        if ($value === null) {
-            return null;
+        if ($value === null || $value instanceof UuidInterface) {
+            return $value;
         }
 
         if (! is_string($value)) {
diff --git a/tests/Behavior/UUIDTest.php b/tests/Behavior/UUIDTest.php
index 39af436..a614499 100644
--- a/tests/Behavior/UUIDTest.php
+++ b/tests/Behavior/UUIDTest.php
@@ -38,6 +38,22 @@ public function testRetrievePropertyReturnsUuidInstance(): void
         );
     }
 
+    public function testRetrievePropertyCanBeAppliedRepeatedly(): void
+    {
+        $behavior = $this->behavior();
+        $uuid = $behavior->retrieveProperty(
+            RamseyUuid::fromString(static::TEST_UUID_VALUE)->getBytes(),
+            static::TEST_COLUMN
+        );
+
+        $this->assertSame($uuid, $behavior->retrieveProperty($uuid, static::TEST_COLUMN));
+
+        $behavior = $this->behavior(true);
+        $uuid = $behavior->retrieveProperty(static::TEST_UUID_VALUE, static::TEST_COLUMN);
+
+        $this->assertSame($uuid, $behavior->retrieveProperty($uuid, static::TEST_COLUMN));
+    }
+
     public function testPersistPropertyReturnsNullWhenValueIsNull(): void
     {
         $this->assertNull($this->behavior()->persistProperty(null, static::TEST_COLUMN));
diff --git a/tests/MillisecondTimestampBehaviorTest.php b/tests/MillisecondTimestampBehaviorTest.php
index a1045e4..07d71dd 100644
--- a/tests/MillisecondTimestampBehaviorTest.php
+++ b/tests/MillisecondTimestampBehaviorTest.php
@@ -15,6 +15,14 @@ public function testFromDbReturnsNullWhenNullIsPassed()
         $this->assertNull((new MillisecondTimestamp([]))->fromDb(null, 'key', null));
     }
 
+    public function testFromDbCanBeAppliedRepeatedly()
+    {
+        $behavior = new MillisecondTimestamp([]);
+        $sometime = $behavior->fromDb(1668002400123, 'key', null);
+
+        $this->assertSame($sometime, $behavior->fromDb($sometime, 'key', null));
+    }
+
     public function testToDbReturnsNullWhenNullIsPassed()
     {
         $this->assertNull((new MillisecondTimestamp([]))->toDb(null, 'key', null));