diff --git a/src/Type/IntegerRangeType.php b/src/Type/IntegerRangeType.php
index 4b9fb037c3d..b41da7851bb 100644
--- a/src/Type/IntegerRangeType.php
+++ b/src/Type/IntegerRangeType.php
@@ -33,6 +33,9 @@
 class IntegerRangeType extends IntegerType implements CompoundType
 {
 
+	/** The first float above PHP_INT_MAX: 2^63 on 64-bit builds, 2^31 on 32-bit ones, exact on both. */
+	private const FLOAT_ABOVE_INT_MAX = PHP_INT_MAX + 1.0;
+
 	private function __construct(private ?int $min, private ?int $max)
 	{
 		parent::__construct();
@@ -90,7 +93,11 @@ public static function createAllSmallerThan($value): Type
 			return self::fromInterval(null, $value, -1);
 		}
 
-		if ($value > PHP_INT_MAX) {
+		// decided on the ceil() about to be cast: comparing $value with PHP_INT_MAX
+		// converts PHP_INT_MAX to float, which rounds it up to 2^63 on 64-bit builds
+		// but keeps it exact on 32-bit ones, where 2147483647.0 is still in range
+		$ceil = ceil($value);
+		if ($ceil >= self::FLOAT_ABOVE_INT_MAX) {
 			return new IntegerType();
 		}
 
@@ -98,7 +105,7 @@ public static function createAllSmallerThan($value): Type
 			return new NeverType();
 		}
 
-		return self::fromInterval(null, (int) ceil($value), -1);
+		return self::fromInterval(null, (int) $ceil, -1);
 	}
 
 	/**
@@ -160,11 +167,13 @@ public static function createAllGreaterThanOrEqualTo($value): Type
 			return new IntegerType();
 		}
 
-		if ($value > PHP_INT_MAX) {
+		// decided on the ceil() about to be cast, like createAllSmallerThan()
+		$ceil = ceil($value);
+		if ($ceil >= self::FLOAT_ABOVE_INT_MAX) {
 			return new NeverType();
 		}
 
-		return self::fromInterval((int) ceil($value), null);
+		return self::fromInterval((int) $ceil, null);
 	}
 
 	public function getMin(): ?int
diff --git a/tests/PHPStan/Analyser/nsrt/integer-range-float-two-to-the-63.php b/tests/PHPStan/Analyser/nsrt/integer-range-float-two-to-the-63.php
new file mode 100644
index 00000000000..b914af2df34
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/integer-range-float-two-to-the-63.php
@@ -0,0 +1,43 @@
+<?php declare(strict_types = 1);
+
+namespace IntegerRangeFloatTwoToThe63;
+
+use function PHPStan\Testing\assertType;
+
+function smaller(int $i): void
+{
+	if ($i < 9.2233720368547758E18) {
+		assertType('int', $i);
+	} else {
+		assertType('*NEVER*', $i);
+	}
+	assertType('int', $i);
+}
+
+function greaterOrEqual(int $i): void
+{
+	if ($i >= 9.2233720368547758E18) {
+		assertType('*NEVER*', $i);
+	} else {
+		assertType('int', $i);
+	}
+	assertType('int', $i);
+}
+
+function smallerOrEqual(int $i): void
+{
+	if ($i <= 9.2233720368547758E18) {
+		assertType('int', $i);
+	} else {
+		assertType('*NEVER*', $i);
+	}
+}
+
+function greater(int $i): void
+{
+	if ($i > 9.2233720368547758E18) {
+		assertType('*NEVER*', $i);
+	} else {
+		assertType('int', $i);
+	}
+}
diff --git a/tests/PHPStan/Type/IntegerRangeTypeTest.php b/tests/PHPStan/Type/IntegerRangeTypeTest.php
new file mode 100644
index 00000000000..e00d2c5224f
--- /dev/null
+++ b/tests/PHPStan/Type/IntegerRangeTypeTest.php
@@ -0,0 +1,136 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Type;
+
+use PHPStan\Testing\PHPStanTestCase;
+use PHPUnit\Framework\Attributes\DataProvider;
+use RuntimeException;
+use function restore_error_handler;
+use function set_error_handler;
+use const PHP_INT_MAX;
+use const PHP_INT_MIN;
+use const PHP_INT_SIZE;
+
+class IntegerRangeTypeTest extends PHPStanTestCase
+{
+
+	public static function dataCreateFromFloat(): iterable
+	{
+		// 2**63 is PHP_INT_MAX + 1, the smallest float greater than every int
+		yield '2**63' => [
+			9.2233720368547758E18,
+			'int',
+			'int',
+			'*NEVER*',
+			'*NEVER*',
+		];
+
+		// the largest float smaller than 2**63
+		yield '2**63 - 1024' => [
+			9.2233720368547748E18,
+			'int<min, 9223372036854774783>',
+			'int<min, 9223372036854774784>',
+			'int<9223372036854774785, max>',
+			'int<9223372036854774784, max>',
+		];
+
+		// -2**63 is exactly PHP_INT_MIN
+		yield '-2**63' => [
+			-9.2233720368547758E18,
+			'*NEVER*',
+			'-9223372036854775808',
+			'int<-9223372036854775807, max>',
+			'int',
+		];
+
+		// the largest float smaller than -2**63
+		yield '-2**63 - 2048' => [
+			-9.2233720368547779E18,
+			'*NEVER*',
+			'*NEVER*',
+			'int',
+			'int',
+		];
+	}
+
+	#[DataProvider('dataCreateFromFloat')]
+	public function testCreateFromFloat(
+		float $value,
+		string $expectedSmallerThan,
+		string $expectedSmallerThanOrEqualTo,
+		string $expectedGreaterThan,
+		string $expectedGreaterThanOrEqualTo,
+	): void
+	{
+		if (PHP_INT_SIZE !== 8) {
+			$this->markTestSkipped('The bounds are those of a 64-bit int.');
+		}
+
+		$this->assertSame([
+			'createAllSmallerThan' => $expectedSmallerThan,
+			'createAllSmallerThanOrEqualTo' => $expectedSmallerThanOrEqualTo,
+			'createAllGreaterThan' => $expectedGreaterThan,
+			'createAllGreaterThanOrEqualTo' => $expectedGreaterThanOrEqualTo,
+		], [
+			'createAllSmallerThan' => IntegerRangeType::createAllSmallerThan($value)->describe(VerbosityLevel::precise()),
+			'createAllSmallerThanOrEqualTo' => IntegerRangeType::createAllSmallerThanOrEqualTo($value)->describe(VerbosityLevel::precise()),
+			'createAllGreaterThan' => IntegerRangeType::createAllGreaterThan($value)->describe(VerbosityLevel::precise()),
+			'createAllGreaterThanOrEqualTo' => IntegerRangeType::createAllGreaterThanOrEqualTo($value)->describe(VerbosityLevel::precise()),
+		]);
+	}
+
+	public static function dataFloatBounds(): iterable
+	{
+		$smallerThan = static fn (float $value): Type => IntegerRangeType::createAllSmallerThan($value);
+		$smallerThanOrEqualTo = static fn (float $value): Type => IntegerRangeType::createAllSmallerThanOrEqualTo($value);
+		$greaterThan = static fn (float $value): Type => IntegerRangeType::createAllGreaterThan($value);
+		$greaterThanOrEqualTo = static fn (float $value): Type => IntegerRangeType::createAllGreaterThanOrEqualTo($value);
+
+		// PHP_INT_MAX + 1.0 is the first float above PHP_INT_MAX on any int width, and
+		// (float) PHP_INT_MIN is exact on any int width
+		$aboveMax = PHP_INT_MAX + 1.0;
+		yield [$smallerThan, $aboveMax, 'int'];
+		yield [$smallerThanOrEqualTo, $aboveMax, 'int'];
+		yield [$greaterThan, $aboveMax, '*NEVER*'];
+		yield [$greaterThanOrEqualTo, $aboveMax, '*NEVER*'];
+		yield [$smallerThan, (float) PHP_INT_MIN, '*NEVER*'];
+		yield [$smallerThanOrEqualTo, (float) PHP_INT_MIN, (string) PHP_INT_MIN];
+		yield [$greaterThan, (float) PHP_INT_MIN, 'int<' . (PHP_INT_MIN + 1) . ', max>'];
+		yield [$greaterThanOrEqualTo, (float) PHP_INT_MIN, 'int'];
+
+		// (float) PHP_INT_MAX is 2^63 on 64-bit builds (above every int) and exact on 32-bit
+		// ones; so is PHP_INT_MAX - 0.5, which is PHP_INT_MAX - 1 + 0.5 on 32-bit builds
+		$maxIsExact = PHP_INT_SIZE < 8;
+		yield [$smallerThan, (float) PHP_INT_MAX, $maxIsExact ? 'int<min, ' . (PHP_INT_MAX - 1) . '>' : 'int'];
+		yield [$smallerThanOrEqualTo, (float) PHP_INT_MAX, 'int'];
+		yield [$greaterThan, (float) PHP_INT_MAX, '*NEVER*'];
+		yield [$greaterThanOrEqualTo, (float) PHP_INT_MAX, $maxIsExact ? (string) PHP_INT_MAX : '*NEVER*'];
+		yield [$smallerThan, PHP_INT_MAX - 0.5, $maxIsExact ? 'int<min, ' . (PHP_INT_MAX - 1) . '>' : 'int'];
+		yield [$greaterThanOrEqualTo, PHP_INT_MAX - 0.5, $maxIsExact ? (string) PHP_INT_MAX : '*NEVER*'];
+
+		// between PHP_INT_MAX and the next int on 32-bit builds, 2^63 on 64-bit ones: its
+		// ceil() is past the int range either way
+		yield [$smallerThan, PHP_INT_MAX + 0.5, 'int'];
+		yield [$greaterThanOrEqualTo, PHP_INT_MAX + 0.5, '*NEVER*'];
+
+		yield [$smallerThan, 2.5, 'int<min, 2>'];
+		yield [$greaterThan, 2.5, 'int<3, max>'];
+	}
+
+	/**
+	 * @param callable(float): Type $factory
+	 */
+	#[DataProvider('dataFloatBounds')]
+	public function testFloatBounds(callable $factory, float $value, string $expected): void
+	{
+		set_error_handler(static function (int $errno, string $errstr): bool {
+			throw new RuntimeException($errstr);
+		});
+		try {
+			$this->assertSame($expected, $factory($value)->describe(VerbosityLevel::precise()));
+		} finally {
+			restore_error_handler();
+		}
+	}
+
+}