diff --git a/src/Rules/Arrays/DuplicateKeysInLiteralArraysRule.php b/src/Rules/Arrays/DuplicateKeysInLiteralArraysRule.php
index 0d32b21381..c05440f892 100644
--- a/src/Rules/Arrays/DuplicateKeysInLiteralArraysRule.php
+++ b/src/Rules/Arrays/DuplicateKeysInLiteralArraysRule.php
@@ -83,7 +83,7 @@ public function processNode(Node $node, Scope $scope): array
 				}
 			}
 
-			$keyValues = $keyType->getConstantScalarValues();
+			$keyValues = $keyType->toArrayKey()->getConstantScalarValues();
 			if (count($keyValues) === 0) {
 				$autoGeneratedIndex = false;
 				continue;
diff --git a/tests/PHPStan/Rules/Arrays/DuplicateKeysInLiteralArraysRuleTest.php b/tests/PHPStan/Rules/Arrays/DuplicateKeysInLiteralArraysRuleTest.php
index a01e02424d..03a01b9250 100644
--- a/tests/PHPStan/Rules/Arrays/DuplicateKeysInLiteralArraysRuleTest.php
+++ b/tests/PHPStan/Rules/Arrays/DuplicateKeysInLiteralArraysRuleTest.php
@@ -93,6 +93,10 @@ public function testDuplicateKeys(): void
 				"Array has 2 duplicate keys with value 'baz' (\$key, 'baz').",
 				171,
 			],
+			[
+				"Array has 5 duplicate keys with value 1 (1, '1', true, 1.0, 1.1).",
+				179,
+			],
 		]);
 	}
 
diff --git a/tests/PHPStan/Rules/Arrays/data/duplicate-keys.php b/tests/PHPStan/Rules/Arrays/data/duplicate-keys.php
index 7a73af9da9..8e7725d5b8 100644
--- a/tests/PHPStan/Rules/Arrays/data/duplicate-keys.php
+++ b/tests/PHPStan/Rules/Arrays/data/duplicate-keys.php
@@ -172,4 +172,15 @@ public function sureDuplicate4(string $key): void
 			'baz' => 'baz',
 		];
 	}
+
+	public function duplicateWithCast(): void
+	{
+		$a = [
+			1 => 'foo',
+			'1' => 'bar',
+			true => 'baz',
+			1.0 => 'some',
+			1.1 => 'thing'
+		];
+	}
 }