diff --git a/src/Type/Php/PathinfoFunctionDynamicReturnTypeExtension.php b/src/Type/Php/PathinfoFunctionDynamicReturnTypeExtension.php
index 4c5193d812..11a5f74752 100644
--- a/src/Type/Php/PathinfoFunctionDynamicReturnTypeExtension.php
+++ b/src/Type/Php/PathinfoFunctionDynamicReturnTypeExtension.php
@@ -58,14 +58,20 @@ public function getTypeFromFunctionCall(
 		$scalarValues = $flagsType->getConstantScalarValues();
 		if ($scalarValues !== []) {
 			$pathInfoAll = $this->getConstant('PATHINFO_ALL');
+			if ($pathInfoAll === null) {
+				return null;
+			}
 
+			$result = [];
 			foreach ($scalarValues as $scalarValue) {
-				if ($pathInfoAll !== null && $scalarValue === $pathInfoAll) {
-					return $arrayType;
+				if ($scalarValue === $pathInfoAll) {
+					$result[] = $arrayType;
+				} else {
+					$result[] = new StringType();
 				}
 			}
 
-			return new StringType();
+			return TypeCombinator::union(...$result);
 		}
 
 		return TypeCombinator::union($arrayType, new StringType());
diff --git a/tests/PHPStan/Analyser/nsrt/pathinfo.php b/tests/PHPStan/Analyser/nsrt/pathinfo.php
index 94a5e19d8b..b58886e6d1 100644
--- a/tests/PHPStan/Analyser/nsrt/pathinfo.php
+++ b/tests/PHPStan/Analyser/nsrt/pathinfo.php
@@ -20,4 +20,7 @@ function doFoo(string $s, int $i, $flag) {
 	if ($i === PATHINFO_ALL) {
 		assertType('array{dirname?: string, basename: string, extension?: string, filename: string}', pathinfo($s, $i));
 	}
+	if ($i === PATHINFO_ALL || $i === PATHINFO_DIRNAME) {
+		assertType('array{dirname?: string, basename: string, extension?: string, filename: string}|string', pathinfo($s, $i));
+	}
 }