Index: src/OFMutableString.h
==================================================================
--- src/OFMutableString.h
+++ src/OFMutableString.h
@@ -44,11 +44,11 @@
  * @brief Appends the specified characters to the OFMutableString.
  *
  * @param characters An array of characters to append
  * @param length The length of the array of characters
  */
-- (void)appendCharacters: (of_unichar_t*)characters
+- (void)appendCharacters: (const of_unichar_t*)characters
 		  length: (size_t)length;
 
 /*!
  * @brief Appends a UTF-8 encoded C string to the OFMutableString.
  *

Index: src/OFMutableString.m
==================================================================
--- src/OFMutableString.m
+++ src/OFMutableString.m
@@ -335,11 +335,11 @@
 {
 	[self insertString: string
 		   atIndex: [self length]];
 }
 
-- (void)appendCharacters: (of_unichar_t*)characters
+- (void)appendCharacters: (const of_unichar_t*)characters
 		  length: (size_t)length
 {
 	void *pool = objc_autoreleasePoolPush();
 
 	[self appendString: [OFString stringWithCharacters: characters

Index: src/OFMutableString_UTF8.m
==================================================================
--- src/OFMutableString_UTF8.m
+++ src/OFMutableString_UTF8.m
@@ -381,11 +381,11 @@
 			_s->isUTF8 = true;
 	} else
 		_s->isUTF8 = true;
 }
 
-- (void)appendCharacters: (of_unichar_t*)characters
+- (void)appendCharacters: (const of_unichar_t*)characters
 		  length: (size_t)length
 {
 	char *tmp;
 
 	tmp = [self allocMemoryWithSize: (length * 4) + 1];