diff --git a/src/Analyser/TypeSpecifier.php b/src/Analyser/TypeSpecifier.php
index 5439383672e..09f1c184c5b 100644
--- a/src/Analyser/TypeSpecifier.php
+++ b/src/Analyser/TypeSpecifier.php
@@ -329,15 +329,7 @@ public function specifyTypesInCondition(
 					&& isset($exprNode->getArgs()[0])
 					&& $constantType instanceof ConstantStringType
 				) {
-					return $this->specifyTypesInCondition(
-						$scope,
-						new Instanceof_(
-							$exprNode->getArgs()[0]->value,
-							new Name($constantType->getValue()),
-						),
-						$context,
-						$rootExpr,
-					);
+					return $this->specifyTypesInCondition($scope, new Expr\BinaryOp\Identical($expr->left, $expr->right), $context, $rootExpr);
 				}
 			}
 
@@ -1042,6 +1034,23 @@ private function specifyTypesForConstantStringBinaryExpression(
 			}
 		}
 
+		if (
+			$exprNode instanceof FuncCall
+			&& $exprNode->name instanceof Name
+			&& strtolower($exprNode->name->toString()) === 'get_class'
+			&& isset($exprNode->getArgs()[0])
+		) {
+			return $this->specifyTypesInCondition(
+				$scope,
+				new Instanceof_(
+					$exprNode->getArgs()[0]->value,
+					new Name($constantType->getValue()),
+				),
+				$context,
+				$rootExpr,
+			);
+		}
+
 		if (
 			$exprNode instanceof FuncCall
 			&& $exprNode->name instanceof Name
diff --git a/tests/PHPStan/Analyser/NodeScopeResolverTest.php b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
index 1c2b7a69c6f..1b776622e8b 100644
--- a/tests/PHPStan/Analyser/NodeScopeResolverTest.php
+++ b/tests/PHPStan/Analyser/NodeScopeResolverTest.php
@@ -1053,6 +1053,7 @@ public function dataFileAsserts(): iterable
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/array-offset-unset.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-8008.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-5552.php');
+		yield from $this->gatherAssertTypes(__DIR__ . '/data/bug-1239.php');
 	}
 
 	/**
diff --git a/tests/PHPStan/Analyser/data/bug-1239.php b/tests/PHPStan/Analyser/data/bug-1239.php
new file mode 100644
index 00000000000..588f421123d
--- /dev/null
+++ b/tests/PHPStan/Analyser/data/bug-1239.php
@@ -0,0 +1,23 @@
+<?php
+
+namespace Bug1239;
+
+use function PHPStan\Testing\assertType;
+
+class Foo
+{
+	public function __construct()
+	{
+		if (get_class($this) === Bar::class) {
+			assertType('$this(Bug1239\Foo)&Bug1239\Bar', $this);
+			$this->bat();
+		}
+	}
+}
+
+class Bar extends Foo
+{
+	public function bat(): void
+	{
+	}
+}