Index: src/OFConstantString.m
==================================================================
--- src/OFConstantString.m
+++ src/OFConstantString.m
@@ -612,10 +612,17 @@
 {
 	[self finishInitialization];
 
 	return [self decomposedStringWithCanonicalMapping];
 }
+
+- (OFString *)decomposedStringWithCompatibilityMapping
+{
+	[self finishInitialization];
+
+	return [self decomposedStringWithCompatibilityMapping];
+}
 #endif
 
 - (void)writeToFile: (OFString *)path
 {
 	[self finishInitialization];

Index: src/OFString.h
==================================================================
--- src/OFString.h
+++ src/OFString.h
@@ -1107,10 +1107,17 @@
  * @brief Returns the string in Unicode Normalization Form D (NFD).
  *
  * @return The string in Unicode Normalization Form D (NFD)
  */
 - (OFString *)decomposedStringWithCanonicalMapping;
+
+/*!
+ * @brief Returns the string in Unicode Normalization Form KD (NFKD).
+ *
+ * @return The string in Unicode Normalization Form KD (NFKD)
+ */
+- (OFString *)decomposedStringWithCompatibilityMapping;
 #endif
 
 #ifdef OF_HAVE_FILES
 /*!
  * @brief Writes the string into the specified file using UTF-8 encoding.

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -344,10 +344,41 @@
 
 	objc_autoreleasePoolPop(pool);
 
 	return [ret autorelease];
 }
+
+static OFString *
+decomposedString(OFString *self, const char *const *const *table, size_t size)
+{
+	OFMutableString *ret = [OFMutableString string];
+	void *pool = objc_autoreleasePoolPush();
+	const of_unichar_t *characters = [self characters];
+	size_t length = [self length];
+
+	for (size_t i = 0; i < length; i++) {
+		of_unichar_t c = characters[i];
+		const char *const *page;
+
+		if (c >= size) {
+			[ret appendCharacters: &c
+				       length: 1];
+			continue;
+		}
+
+		page = table[c >> 8];
+		if (page != NULL && page[c & 0xFF] != NULL)
+			[ret appendUTF8String: page[c & 0xFF]];
+		else
+			[ret appendCharacters: &c
+				       length: 1];
+	}
+
+	objc_autoreleasePoolPop(pool);
+
+	return ret;
+}
 
 static struct {
 	Class isa;
 } placeholder;
 
@@ -2713,36 +2744,18 @@
 }
 
 #ifdef OF_HAVE_UNICODE_TABLES
 - (OFString *)decomposedStringWithCanonicalMapping
 {
-	OFMutableString *ret = [OFMutableString string];
-	void *pool = objc_autoreleasePoolPush();
-	const of_unichar_t *characters = [self characters];
-	size_t length = [self length];
-
-	for (size_t i = 0; i < length; i++) {
-		of_unichar_t c = characters[i];
-		const char *const *table;
-
-		if (c >= OF_UNICODE_DECOMPOSITION_TABLE_SIZE) {
-			[ret appendCharacters: &c
-				       length: 1];
-			continue;
-		}
-
-		table = of_unicode_decomposition_table[c >> 8];
-		if (table != NULL && table[c & 0xFF] != NULL)
-			[ret appendUTF8String: table[c & 0xFF]];
-		else
-			[ret appendCharacters: &c
-				       length: 1];
-	}
-
-	objc_autoreleasePoolPop(pool);
-
-	return ret;
+	return decomposedString(self, of_unicode_decomposition_table,
+	    OF_UNICODE_DECOMPOSITION_TABLE_SIZE);
+}
+
+- (OFString *)decomposedStringWithCompatibilityMapping
+{
+	return decomposedString(self, of_unicode_decomposition_compat_table,
+	    OF_UNICODE_DECOMPOSITION_COMPAT_TABLE_SIZE);
 }
 #endif
 
 #ifdef OF_HAVE_FILES
 - (void)writeToFile: (OFString *)path

Index: tests/OFStringTests.m
==================================================================
--- tests/OFStringTests.m
+++ tests/OFStringTests.m
@@ -899,13 +899,19 @@
 	    (s[0] = [mutableStringClass stringWithString: whitespace[0]]) &&
 	    R([s[0] deleteEnclosingWhitespaces]) && [s[0] isEqual: @"asd"] &&
 	    (s[0] = [mutableStringClass stringWithString: whitespace[1]]) &&
 	    R([s[0] deleteEnclosingWhitespaces]) && [s[0] isEqual: @""])
 
+#ifdef OF_HAVE_UNICODE_TABLES
 	TEST(@"-[decomposedStringWithCanonicalMapping]",
-	    [[@"H\xC3\xA4ll\xC3\xB6" decomposedStringWithCanonicalMapping]
-	    isEqual: @"H\x61\xCC\x88ll\x6F\xCC\x88"]);
+	    [[@"H\xC3\xA4llj\xC3\xB6" decomposedStringWithCanonicalMapping]
+	    isEqual: @"H\x61\xCC\x88llj\x6F\xCC\x88"]);
+
+	TEST(@"-[decomposedStringWithCompatibilityMapping]",
+	    [[@"H\xC3\xA4llj\xC3\xB6" decomposedStringWithCompatibilityMapping]
+	    isEqual: @"H\x61\xCC\x88llj\x6F\xCC\x88"]);
+#endif
 
 	TEST(@"-[stringByXMLEscaping]",
 	    (is = [C(@"<hello> &world'\"!&") stringByXMLEscaping]) &&
 	    [is isEqual: @"&lt;hello&gt; &amp;world&apos;&quot;!&amp;"])