Index: src/OFMutableURL.h
==================================================================
--- src/OFMutableURL.h
+++ src/OFMutableURL.h
@@ -141,10 +141,27 @@
  *
  * @return A new, autoreleased OFMutableURL
  */
 + (instancetype)URL;
 
+/*!
+ * @brief Appends the specified path component.
+ *
+ * @param component The component to append
+ */
+- (void)appendPathComponent: (OFString *)component;
+
+/*!
+ * @brief Appends the specified path component.
+ *
+ * @param component The component to append
+ * @param isDirectory Whether the path is a directory, in which case a slash is
+ *		      appened if there is no slash yet
+ */
+- (void)appendPathComponent: (OFString *)component
+		isDirectory: (bool)isDirectory;
+
 /*!
  * @brief Resolves relative sub paths.
  */
 - (void)standardizePath;
 

Index: src/OFMutableURL.m
==================================================================
--- src/OFMutableURL.m
+++ src/OFMutableURL.m
@@ -17,10 +17,13 @@
 
 #include "config.h"
 
 #import "OFMutableURL.h"
 #import "OFArray.h"
+#ifdef OF_HAVE_FILES
+# import "OFFileManager.h"
+#endif
 #import "OFNumber.h"
 #import "OFString.h"
 
 #import "OFInvalidFormatException.h"
 
@@ -253,10 +256,65 @@
 
 	[copy makeImmutable];
 
 	return copy;
 }
+
+- (void)appendPathComponent: (OFString *)component
+{
+	[self appendPathComponent: component
+		      isDirectory: false];
+
+#ifdef OF_HAVE_FILES
+	if ([_URLEncodedScheme isEqual: @"file"] &&
+	    ![_URLEncodedPath hasSuffix: @"/"] &&
+	    [[OFFileManager defaultManager] directoryExistsAtURL: self]) {
+		void *pool = objc_autoreleasePoolPush();
+		OFString *path = [_URLEncodedPath
+		    stringByAppendingString: @"/"];
+
+		[_URLEncodedPath release];
+		_URLEncodedPath = [path retain];
+
+		objc_autoreleasePoolPop(pool);
+	}
+#endif
+}
+
+- (void)appendPathComponent: (OFString *)component
+		isDirectory: (bool)isDirectory
+{
+	void *pool;
+	OFString *path;
+
+	if ([component isEqual: @"/"] && [_URLEncodedPath hasSuffix: @"/"])
+		return;
+
+	pool = objc_autoreleasePoolPush();
+	component = [component stringByURLEncodingWithAllowedCharacters:
+	    [OFCharacterSet URLPathAllowedCharacterSet]];
+
+#if defined(OF_WINDOWS) || defined(OF_MSDOS)
+	if ([_URLEncodedPath hasSuffix: @"/"] ||
+	    ([_URLEncodedScheme isEqual: @"file"] &&
+	    [_URLEncodedPath hasSuffix: @":"]))
+#else
+	if ([_URLEncodedPath hasSuffix: @"/"])
+#endif
+		path = [_URLEncodedPath stringByAppendingString: component];
+	else
+		path = [_URLEncodedPath
+		    stringByAppendingFormat: @"/%@", component];
+
+	if (isDirectory && ![path hasSuffix: @"/"])
+		path = [path stringByAppendingString: @"/"];
+
+	[_URLEncodedPath release];
+	_URLEncodedPath = [path retain];
+
+	objc_autoreleasePoolPop(pool);
+}
 
 - (void)standardizePath
 {
 	void *pool;
 	OFMutableArray OF_GENERIC(OFString *) *array;

Index: src/OFURL.m
==================================================================
--- src/OFURL.m
+++ src/OFURL.m
@@ -1138,76 +1138,30 @@
 
 	return [path autorelease];
 }
 #endif
 
-- (OFMutableURL *)of_URLByAppendingPathComponent: (OFString *)component
-{
-	OFMutableURL *ret = [[self mutableCopy] autorelease];
-	void *pool;
-	OFMutableString *URLEncodedPath;
-
-	if ([component hasPrefix: @"/"]) {
-		ret.path = component;
-		return ret;
-	}
-
-	pool = objc_autoreleasePoolPush();
-	URLEncodedPath = [[self.URLEncodedPath mutableCopy] autorelease];
-
-	if (![URLEncodedPath hasSuffix: @"/"])
-		[URLEncodedPath appendString: @"/"];
-
-	[URLEncodedPath appendString:
-	    [component stringByURLEncodingWithAllowedCharacters:
-	    [OFCharacterSet URLPathAllowedCharacterSet]]];
-
-	ret.URLEncodedPath = URLEncodedPath;
-
-	objc_autoreleasePoolPop(pool);
-
-	return ret;
-}
-
 - (OFURL *)URLByAppendingPathComponent: (OFString *)component
 {
-	OFMutableURL *ret = [self of_URLByAppendingPathComponent: component];
-
-#ifdef OF_HAVE_FILES
-	if ([ret.scheme isEqual: @"file"]) {
-		void *pool = objc_autoreleasePoolPush();
-
-		if ([[OFFileManager defaultManager] directoryExistsAtURL: ret])
-			ret.URLEncodedPath =
-			    [ret.URLEncodedPath stringByAppendingString: @"/"];
-
-		objc_autoreleasePoolPop(pool);
-	}
-#endif
-
-	[ret makeImmutable];
-
-	return ret;
+	OFMutableURL *URL = [[self mutableCopy] autorelease];
+
+	[URL appendPathComponent: component];
+	[URL makeImmutable];
+
+	return URL;
 }
 
 - (OFURL *)URLByAppendingPathComponent: (OFString *)component
 			   isDirectory: (bool)isDirectory
 {
-	OFMutableURL *ret = [self of_URLByAppendingPathComponent: component];
-
-	if (isDirectory) {
-		void *pool = objc_autoreleasePoolPush();
-
-		ret.URLEncodedPath =
-		    [ret.URLEncodedPath stringByAppendingString: @"/"];
-
-		objc_autoreleasePoolPop(pool);
-	}
-
-	[ret makeImmutable];
-
-	return ret;
+	OFMutableURL *URL = [[self mutableCopy] autorelease];
+
+	[URL appendPathComponent: component
+		     isDirectory: isDirectory];
+	[URL makeImmutable];
+
+	return URL;
 }
 
 - (OFURL *)URLByStandardizingPath
 {
 	OFMutableURL *URL = [[self mutableCopy] autorelease];

Index: tests/OFURLTests.m
==================================================================
--- tests/OFURLTests.m
+++ tests/OFURLTests.m
@@ -264,23 +264,11 @@
 			    isDirectory: false] isEqual:
 	    [OFURL URLWithString: @"file:///foo/bar/qu%3Fx"]] &&
 	    [[[OFURL URLWithString: @"file:///foo/bar/"]
 	    URLByAppendingPathComponent: @"qu?x"
 			    isDirectory: true] isEqual:
-	    [OFURL URLWithString: @"file:///foo/bar/qu%3Fx/"]] &&
-	    [[[OFURL URLWithString: @"file:///foo/bar/"]
-	    URLByAppendingPathComponent: @"/qux"
-			    isDirectory: false] isEqual:
-	    [OFURL URLWithString: @"file:///qux"]] &&
-	    [[[OFURL URLWithString: @"file:///foo/bar/"]
-	    URLByAppendingPathComponent: @"/qu?x"
-			    isDirectory: false] isEqual:
-	    [OFURL URLWithString: @"file:///qu%3Fx"]] &&
-	    [[[OFURL URLWithString: @"file:///foo/bar/"]
-	    URLByAppendingPathComponent: @"/qu?x"
-			    isDirectory: true] isEqual:
-	    [OFURL URLWithString: @"file:///qu%3Fx/"]])
+	    [OFURL URLWithString: @"file:///foo/bar/qu%3Fx/"]])
 
 	TEST(@"-[URLByStandardizingPath]",
 	    [[[OFURL URLWithString: @"http://foo/bar/.."]
 	    URLByStandardizingPath] isEqual:
 	    [OFURL URLWithString: @"http://foo/"]] &&