Index: src/OFMutableString.h
==================================================================
--- src/OFMutableString.h
+++ src/OFMutableString.h
@@ -85,21 +85,21 @@
 
 /*!
  * @brief Appends a formatted string to the OFMutableString.
  *
  * See printf for the format syntax. As an addition, %@ is available as format
- * specifier for objects.
+ * specifier for objects and %C for of_unichar_t.
  *
  * @param format A format string which generates the string to append
  */
 - (void)appendFormat: (OFConstantString*)format, ...;
 
 /*!
  * @brief Appends a formatted string to the OFMutableString.
  *
  * See printf for the format syntax. As an addition, %@ is available as format
- * specifier for objects.
+ * specifier for objects and %C for of_unichar_t.
  *
  * @param format A format string which generates the string to append
  * @param arguments The arguments used in the format string
  */
 - (void)appendFormat: (OFConstantString*)format

Index: src/OFStream.h
==================================================================
--- src/OFStream.h
+++ src/OFStream.h
@@ -985,11 +985,11 @@
 
 /*!
  * @brief Writes a formatted string into the stream.
  *
  * See printf for the format syntax. As an addition, %@ is available as format
- * specifier for objects.
+ * specifier for objects and %C for of_unichar_t.
  *
  * @param format A string used as format
  * @return The number of bytes written
  */
 - (size_t)writeFormat: (OFConstantString*)format, ...;
@@ -996,11 +996,11 @@
 
 /*!
  * @brief Writes a formatted string into the stream.
  *
  * See printf for the format syntax. As an addition, %@ is available as format
- * specifier for objects.
+ * specifier for objects and %C for of_unichar_t.
  *
  * @param format A string used as format
  * @param arguments The arguments used in the format string
  * @return The number of bytes written
  */

Index: src/OFString.h
==================================================================
--- src/OFString.h
+++ src/OFString.h
@@ -263,11 +263,11 @@
 
 /*!
  * @brief Creates a new OFString from a format string.
  *
  * See printf for the format syntax. As an addition, %@ is available as format
- * specifier for objects.
+ * specifier for objects and %C for of_unichar_t.
  *
  * @param format A string used as format to initialize the OFString
  * @return A new autoreleased OFString
  */
 + (instancetype)stringWithFormat: (OFConstantString*)format, ...;
@@ -492,11 +492,11 @@
 
 /*!
  * @brief Initializes an already allocated OFString with a format string.
  *
  * See printf for the format syntax. As an addition, %@ is available as format
- * specifier for objects.
+ * specifier for objects and %C for of_unichar_t.
  *
  * @param format A string used as format to initialize the OFString
  * @return An initialized OFString
  */
 - initWithFormat: (OFConstantString*)format, ...;
@@ -503,11 +503,11 @@
 
 /*!
  * @brief Initializes an already allocated OFString with a format string.
  *
  * See printf for the format syntax. As an addition, %@ is available as format
- * specifier for objects.
+ * specifier for objects and %C for of_unichar_t.
  *
  * @param format A string used as format to initialize the OFString
  * @param arguments The arguments used in the format string
  * @return An initialized OFString
  */

Index: src/of_asprintf.m
==================================================================
--- src/of_asprintf.m
+++ src/of_asprintf.m
@@ -26,10 +26,12 @@
 
 #include <sys/types.h>
 
 #import "OFString.h"
 
+#import "OFInvalidEncodingException.h"
+
 #import "asprintf.h"
 #import "autorelease.h"
 #import "macros.h"
 
 #define MAX_SUBFORMAT_LEN 64
@@ -310,10 +312,26 @@
 				    "(nil)");
 		} @catch (id e) {
 			free(ctx->buffer);
 			@throw e;
 		}
+
+		break;
+	case 'C':
+		ctx->subformat[ctx->subformatLen - 1] = 's';
+
+		{
+			char buffer[5];
+			size_t len = of_string_utf8_encode(
+			    va_arg(ctx->arguments, of_unichar_t), buffer);
+
+			if (len == 0)
+				@throw [OFInvalidEncodingException exception];
+
+			buffer[len] = 0;
+			tmpLen = asprintf(&tmp, ctx->subformat, buffer);
+		}
 
 		break;
 	case 'd':
 	case 'i':
 		switch (ctx->lengthModifier) {

Index: utils/OFZIP.m
==================================================================
--- utils/OFZIP.m
+++ utils/OFZIP.m
@@ -92,11 +92,11 @@
 			break;
 		case 'h':
 			help(of_stdout, true, 0);
 			break;
 		default:
-			[of_stderr writeFormat: @"%@: Unknown option: -%c\n",
+			[of_stderr writeFormat: @"%@: Unknown option: -%C\n",
 						[OFApplication programName],
 						[optionsParser lastOption]];
 			[OFApplication terminateWithStatus: 1];
 		}
 	}