diff --git a/src/Reflection/InitializerExprTypeResolver.php b/src/Reflection/InitializerExprTypeResolver.php
index 8b38c5a383..589f2d1c0e 100644
--- a/src/Reflection/InitializerExprTypeResolver.php
+++ b/src/Reflection/InitializerExprTypeResolver.php
@@ -611,8 +611,17 @@ public function getBitwiseAndType(Expr $left, Expr $right, callable $getTypeCall
 			return $this->getNeverType($leftType, $rightType);
 		}
 
-		$leftTypes = $leftType->getConstantScalarTypes();
-		$rightTypes = $rightType->getConstantScalarTypes();
+		if ($leftType instanceof IntegerRangeType) {
+			$leftTypes = $leftType->getFiniteTypes();
+		} else {
+			$leftTypes = $leftType->getConstantScalarTypes();
+		}
+		if ($rightType instanceof IntegerRangeType) {
+			$rightTypes = $rightType->getFiniteTypes();
+		} else {
+			$rightTypes = $rightType->getConstantScalarTypes();
+		}
+
 		$leftTypesCount = count($leftTypes);
 		$rightTypesCount = count($rightTypes);
 		if ($leftTypesCount > 0 && $rightTypesCount > 0) {
@@ -680,8 +689,17 @@ public function getBitwiseOrType(Expr $left, Expr $right, callable $getTypeCallb
 			return $this->getNeverType($leftType, $rightType);
 		}
 
-		$leftTypes = $leftType->getConstantScalarTypes();
-		$rightTypes = $rightType->getConstantScalarTypes();
+		if ($leftType instanceof IntegerRangeType) {
+			$leftTypes = $leftType->getFiniteTypes();
+		} else {
+			$leftTypes = $leftType->getConstantScalarTypes();
+		}
+		if ($rightType instanceof IntegerRangeType) {
+			$rightTypes = $rightType->getFiniteTypes();
+		} else {
+			$rightTypes = $rightType->getConstantScalarTypes();
+		}
+
 		$leftTypesCount = count($leftTypes);
 		$rightTypesCount = count($rightTypes);
 		if ($leftTypesCount > 0 && $rightTypesCount > 0) {
@@ -739,8 +757,17 @@ public function getBitwiseXorType(Expr $left, Expr $right, callable $getTypeCall
 			return $this->getNeverType($leftType, $rightType);
 		}
 
-		$leftTypes = $leftType->getConstantScalarTypes();
-		$rightTypes = $rightType->getConstantScalarTypes();
+		if ($leftType instanceof IntegerRangeType) {
+			$leftTypes = $leftType->getFiniteTypes();
+		} else {
+			$leftTypes = $leftType->getConstantScalarTypes();
+		}
+		if ($rightType instanceof IntegerRangeType) {
+			$rightTypes = $rightType->getFiniteTypes();
+		} else {
+			$rightTypes = $rightType->getConstantScalarTypes();
+		}
+
 		$leftTypesCount = count($leftTypes);
 		$rightTypesCount = count($rightTypes);
 		if ($leftTypesCount > 0 && $rightTypesCount > 0) {
diff --git a/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php b/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
index 31bc2859c2..ba4240e047 100644
--- a/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
+++ b/tests/PHPStan/Rules/Properties/TypesAssignedToPropertiesRuleTest.php
@@ -956,6 +956,18 @@ public function testBug13035(): void
 		$this->analyse([__DIR__ . '/data/bug-13035.php'], []);
 	}
 
+	public function testBug7912(): void
+	{
+		$this->checkExplicitMixed = true;
+		$this->checkImplicitMixed = true;
+		$this->analyse([__DIR__ . '/data/bug-7912.php'], [
+			[
+				'Property Bug7912\A::$has (int<0, 1>) does not accept 999.',
+				35,
+			],
+		]);
+	}
+
 	public function testBug13654(): void
 	{
 		$this->checkExplicitMixed = true;
diff --git a/tests/PHPStan/Rules/Properties/data/bug-7912.php b/tests/PHPStan/Rules/Properties/data/bug-7912.php
new file mode 100644
index 0000000000..3bafd8d3ce
--- /dev/null
+++ b/tests/PHPStan/Rules/Properties/data/bug-7912.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Bug7912;
+
+class A
+{
+	/** @var int<0,1> */
+	public int $has = 0;
+
+	/** @var int<0,1> */
+	public int $not = 0;
+}
+
+class B
+{
+	/** @var int<0,1> */
+	public int $has = 1;
+}
+
+$a = new A();
+$b = new B();
+
+// The following versions throw an error, even though | between 0,1 will always be 0,1
+$a->has |= $b->has;
+$a->has = $a->has | $b->has;
+
+// The following versions don't:
+$a->has = 0 | 1;
+$a->has |= 1;
+
+$int = 1;
+$a->has |= $int;
+
+// This properly errors:
+$a->has |= 999;
+
+// And these all work:
+/** @var int<0,1> */
+$c = 0;
+/** @var int<0,1> */
+$e = 1;
+$c |= $e;
+$c |= $a->has;