diff --git a/src/Runtime/Exception/MappingFailedException.php b/src/Runtime/Exception/MappingFailedException.php
index 1189f9e..e7dd40c 100644
--- a/src/Runtime/Exception/MappingFailedException.php
+++ b/src/Runtime/Exception/MappingFailedException.php
@@ -23,11 +23,12 @@
 use function substr;
 use const JSON_PRESERVE_ZERO_FRACTION;
 use const JSON_THROW_ON_ERROR;
+use const JSON_UNESCAPED_SLASHES;
 
 class MappingFailedException extends RuntimeException
 {
 
-    private const JSON_ENCODE_OPTIONS = JSON_PRESERVE_ZERO_FRACTION | JSON_THROW_ON_ERROR;
+    private const JSON_ENCODE_OPTIONS = JSON_PRESERVE_ZERO_FRACTION | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR;
     private const MAX_STRING_LENGTH = 40;
 
     /**
diff --git a/tests/Runtime/Exception/MappingFailedExceptionTest.php b/tests/Runtime/Exception/MappingFailedExceptionTest.php
index e0a7be9..646837a 100644
--- a/tests/Runtime/Exception/MappingFailedExceptionTest.php
+++ b/tests/Runtime/Exception/MappingFailedExceptionTest.php
@@ -71,6 +71,11 @@ public static function provideMessagesData(): iterable
             'Failed to map data at path /foo: Expected int, got "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" (truncated)',
         ];
 
+        yield 'string with slash' => [
+            MappingFailedException::incorrectValue('foo/bar', ['foo'], 'int'),
+            'Failed to map data at path /foo: Expected int, got "foo/bar"',
+        ];
+
         yield 'string with control characters' => [
             MappingFailedException::incorrectValue("foo\x00bar", ['foo'], 'int'),
             'Failed to map data at path /foo: Expected int, got string',