Index: src/OFString+JSONValue.m
==================================================================
--- src/OFString+JSONValue.m
+++ src/OFString+JSONValue.m
@@ -257,11 +257,11 @@
 
 	free(buffer);
 	return nil;
 }
 
-static OF_INLINE OFArray*
+static OF_INLINE OFMutableArray*
 parseArray(const char *restrict *pointer, const char *stop)
 {
 	OFMutableArray *array = [OFMutableArray array];
 
 	if (++(*pointer) >= stop)
@@ -294,18 +294,16 @@
 				return nil;
 		} else if (**pointer != ']')
 			return nil;
 	}
 
-	[array makeImmutable];
-
 	(*pointer)++;
 
 	return array;
 }
 
-static OF_INLINE OFDictionary*
+static OF_INLINE OFMutableDictionary*
 parseDictionary(const char *restrict *pointer, const char *stop)
 {
 	OFMutableDictionary *dictionary = [OFMutableDictionary dictionary];
 
 	if (++(*pointer) >= stop)
@@ -348,12 +346,10 @@
 				return nil;
 		} else if (**pointer != '}')
 			return nil;
 	}
 
-	[dictionary makeImmutable];
-
 	(*pointer)++;
 
 	return dictionary;
 }