Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -2242,18 +2242,25 @@
 
 - (OFArray *)componentsSeparatedByString: (OFString *)delimiter
 				 options: (int)options
 {
 	void *pool;
-	OFMutableArray *array = [OFMutableArray array];
+	OFMutableArray *array;
 	const of_unichar_t *characters, *delimiterCharacters;
 	bool skipEmpty = (options & OF_STRING_SKIP_EMPTY);
 	size_t length = self.length;
 	size_t delimiterLength = delimiter.length;
 	size_t last;
 	OFString *component;
 
+	if (delimiter == nil)
+		@throw [OFInvalidArgumentException exception];
+
+	if (delimiter.length == 0)
+		return [OFArray arrayWithObject: self];
+
+	array = [OFMutableArray array];
 	pool = objc_autoreleasePoolPush();
 
 	characters = self.characters;
 	delimiterCharacters = delimiter.characters;
 

Index: src/OFUTF8String.m
==================================================================
--- src/OFUTF8String.m
+++ src/OFUTF8String.m
@@ -1111,18 +1111,26 @@
 - (OFArray *)componentsSeparatedByString: (OFString *)delimiter
 				 options: (int)options
 {
 	void *pool;
 	OFMutableArray *array;
-	const char *cString = delimiter.UTF8String;
-	size_t cStringLength = delimiter.UTF8StringLength;
+	const char *cString;
+	size_t cStringLength;
 	bool skipEmpty = (options & OF_STRING_SKIP_EMPTY);
 	size_t last;
 	OFString *component;
 
+	if (delimiter == nil)
+		@throw [OFInvalidArgumentException exception];
+
+	if (delimiter.length == 0)
+		return [OFArray arrayWithObject: self];
+
 	array = [OFMutableArray array];
 	pool = objc_autoreleasePoolPush();
+	cString = delimiter.UTF8String;
+	cStringLength = delimiter.UTF8StringLength;
 
 	if (cStringLength > _s->cStringLength) {
 		[array addObject: [[self copy] autorelease]];
 		objc_autoreleasePoolPop(pool);
 

Index: tests/OFStringTests.m
==================================================================
--- tests/OFStringTests.m
+++ tests/OFStringTests.m
@@ -603,11 +603,14 @@
 	    [[a objectAtIndex: i++] isEqual: @"bar"] &&
 	    [[a objectAtIndex: i++] isEqual: @""] &&
 	    [[a objectAtIndex: i++] isEqual: @"baz"] &&
 	    [[a objectAtIndex: i++] isEqual: @""] &&
 	    [[a objectAtIndex: i++] isEqual: @""] &&
-	    a.count == i)
+	    a.count == i &&
+	    (a = [C(@"foo") componentsSeparatedByString: @""]) &&
+	    [[a objectAtIndex: 0] isEqual: @"foo"] &&
+	    a.count == 1)
 
 	i = 0;
 	TEST(@"-[componentsSeparatedByString:options:]",
 	    (a = [C(@"fooXXbarXXXXbazXXXX")
 	    componentsSeparatedByString: @"XX"