diff --git a/CHANGELOG.md b/CHANGELOG.md
index 43ea4f0..74308c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -21,6 +21,13 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Security
 
 
+## [4.0.0-alpha3] - 2020-02-21
+
+### Fixed
+
+* Fix microsecond rounding error on 32-bit systems.
+
+
 ## [4.0.0-alpha2] - 2020-02-21
 
 ### Added
@@ -823,7 +830,8 @@ versions leading up to this release.*
 [ramsey/uuid-doctrine]: https://github.com/ramsey/uuid-doctrine
 [ramsey/uuid-console]: https://github.com/ramsey/uuid-console
 
-[unreleased]: https://github.com/ramsey/uuid/compare/4.0.0-alpha2...HEAD
+[unreleased]: https://github.com/ramsey/uuid/compare/4.0.0-alpha3...HEAD
+[4.0.0-alpha3]: https://github.com/ramsey/uuid/compare/4.0.0-alpha2...4.0.0-alpha3
 [4.0.0-alpha2]: https://github.com/ramsey/uuid/compare/4.0.0-alpha1...4.0.0-alpha2
 [4.0.0-alpha1]: https://github.com/ramsey/uuid/compare/3.9.3...4.0.0-alpha1
 [3.9.3]: https://github.com/ramsey/uuid/compare/3.9.2...3.9.3
diff --git a/src/Converter/Time/GenericTimeConverter.php b/src/Converter/Time/GenericTimeConverter.php
index 6fab086..d5ce5f7 100644
--- a/src/Converter/Time/GenericTimeConverter.php
+++ b/src/Converter/Time/GenericTimeConverter.php
@@ -92,10 +92,8 @@ class GenericTimeConverter implements TimeConverterInterface
             new IntegerValue('122192928000000000')
         );
 
-        // Round down so that the microseconds do not shift the timestamp
-        // into the next second, giving us the wrong Unix timestamp.
         $unixTimestamp = $this->calculator->divide(
-            RoundingMode::DOWN,
+            RoundingMode::HALF_UP,
             6,
             $epochNanoseconds,
             new IntegerValue('10000000')
diff --git a/src/Converter/Time/PhpTimeConverter.php b/src/Converter/Time/PhpTimeConverter.php
index 4fa0191..607102b 100644
--- a/src/Converter/Time/PhpTimeConverter.php
+++ b/src/Converter/Time/PhpTimeConverter.php
@@ -154,9 +154,22 @@ class PhpTimeConverter implements TimeConverterInterface
             return [];
         }
 
+        $microseconds = $split[1];
+
+        // Ensure the microseconds are no longer than 6 digits. If they are,
+        // truncate the number to the first 6 digits and round up, if needed.
+        if (strlen($microseconds) > 6) {
+            $roundingDigit = (int) substr($microseconds, 6, 1);
+            $microseconds = (int) substr($microseconds, 0, 6);
+
+            if ($roundingDigit >= 5) {
+                $microseconds++;
+            }
+        }
+
         return [
             'sec' => $split[0],
-            'usec' => str_pad($split[1], 6, '0', STR_PAD_RIGHT),
+            'usec' => str_pad((string) $microseconds, 6, '0', STR_PAD_RIGHT),
         ];
     }
 }
diff --git a/src/Rfc4122/UuidV1.php b/src/Rfc4122/UuidV1.php
index aa3d8c7..4989915 100644
--- a/src/Rfc4122/UuidV1.php
+++ b/src/Rfc4122/UuidV1.php
@@ -78,23 +78,12 @@ final class UuidV1 extends Uuid implements UuidInterface
     {
         $time = $this->timeConverter->convertTime($this->fields->getTimestamp());
 
-        $microseconds = $time->getMicroSeconds()->toString();
-
-        if (strlen($microseconds) > 6) {
-            $roundingDigit = (int) substr($microseconds, 6, 1);
-            $microseconds = (int) substr($microseconds, 0, 6);
-
-            if ($roundingDigit >= 5) {
-                $microseconds++;
-            }
-        }
-
         try {
             return new DateTimeImmutable(
                 '@'
                 . $time->getSeconds()->toString()
                 . '.'
-                . str_pad((string) $microseconds, 6, '0', STR_PAD_LEFT)
+                . str_pad($time->getMicroSeconds()->toString(), 6, '0', STR_PAD_LEFT)
             );
         } catch (Throwable $e) {
             throw new DateTimeException($e->getMessage(), (int) $e->getCode(), $e);
diff --git a/tests/UuidTest.php b/tests/UuidTest.php
index d3347f4..24cdd88 100644
--- a/tests/UuidTest.php
+++ b/tests/UuidTest.php
@@ -7,9 +7,15 @@ namespace Ramsey\Uuid\Test;
 use Brick\Math\BigDecimal;
 use Brick\Math\RoundingMode;
 use DateTimeInterface;
+use Mockery;
 use PHPUnit\Framework\MockObject\MockObject;
+use Ramsey\Uuid\Builder\DefaultUuidBuilder;
+use Ramsey\Uuid\Codec\StringCodec;
 use Ramsey\Uuid\Codec\TimestampFirstCombCodec;
 use Ramsey\Uuid\Codec\TimestampLastCombCodec;
+use Ramsey\Uuid\Converter\Number\BigNumberConverter;
+use Ramsey\Uuid\Converter\TimeConverterInterface;
+use Ramsey\Uuid\Exception\DateTimeException;
 use Ramsey\Uuid\Exception\InvalidArgumentException;
 use Ramsey\Uuid\Exception\InvalidUuidStringException;
 use Ramsey\Uuid\Exception\UnsupportedOperationException;
@@ -1464,6 +1470,33 @@ class UuidTest extends TestCase
         $this->assertEquals($uuid->getVersion(), Uuid::UUID_TYPE_HASH_SHA1);
     }
 
+    public function testGetDateTimeThrowsExceptionWhenDateTimeCannotParseDate(): void
+    {
+        $numberConverter = new BigNumberConverter();
+        $timeConverter = Mockery::mock(TimeConverterInterface::class);
+
+        $timeConverter
+            ->shouldReceive('convertTime')
+            ->once()
+            ->andReturn(new Time(1234567890, '1234567'));
+
+        $builder = new DefaultUuidBuilder($numberConverter, $timeConverter);
+        $codec = new StringCodec($builder);
+
+        $factory = new UuidFactory();
+        $factory->setCodec($codec);
+
+        $uuid = $factory->fromString('b1484596-25dc-11ea-978f-2e728ce88125');
+
+        $this->expectException(DateTimeException::class);
+        $this->expectExceptionMessage(
+            'DateTimeImmutable::__construct(): Failed to parse time string '
+            . '(@1234567890.1234567) at position 18 (7): Unexpected character'
+        );
+
+        $uuid->getDateTime();
+    }
+
     /**
      * @param class-string $expectedClass
      * @param mixed[] $args