Index: src/OFDictionary.m
==================================================================
--- src/OFDictionary.m
+++ src/OFDictionary.m
@@ -111,26 +111,26 @@
 {
 	uint32_t hash = [key hash] & (size - 1);
 	of_list_object_t *iter;
 
 	if (data[hash] == nil)
-		return nil;
+		@throw [OFNotInSetException newWithClass: isa];
 
 	for (iter = [data[hash] first]; iter != NULL; iter = iter->next->next)
 		if ([iter->object isEqual: key])
 			return iter->next->object;
 
-	return nil;
+	@throw [OFNotInSetException newWithClass: isa];
 }
 
 - remove: (OFObject*)key
 {
 	uint32_t hash = [key hash] & (size - 1);
 	of_list_object_t *iter;
 
 	if (data[hash] == nil)
-		return self; // FIXME: Throw exception?
+		@throw [OFNotInSetException newWithClass: isa];
 
 	for (iter = [data[hash] first]; iter != NULL; iter = iter->next->next) {
 		if ([iter->object isEqual: key]) {
 			[data[hash] remove: iter->next];
 			[data[hash] remove: iter];
@@ -137,15 +137,15 @@
 
 			return self;
 		}
 	}
 
-	return self;  // FIXME: Throw exception?
+	@throw [OFNotInSetException newWithClass: isa];
 }
 
 /* FIXME: Implement this! */
 /*
 - (BOOL)isEqual
 {
 }
 */
 @end

Index: src/OFExceptions.h
==================================================================
--- src/OFExceptions.h
+++ src/OFExceptions.h
@@ -210,11 +210,17 @@
 @end
 
 /**
  * An OFException indicating that initializing something failed.
  */
-@interface OFInitializationFailedException: OFException
+@interface OFInitializationFailedException: OFException {}
+@end
+
+/**
+ * An OFException indicating that the requested key is not in the set.
+ */
+@interface OFNotInSetException: OFException {}
 @end
 
 /**
  * An OFException indicating the file couldn't be opened.
  */

Index: src/OFExceptions.m
==================================================================
--- src/OFExceptions.m
+++ src/OFExceptions.m
@@ -267,10 +267,23 @@
 	if (string != NULL)
 		return string;
 
 	asprintf(&string, "Initialization failed for class %s!", [class name]);
 
+	return string;
+}
+@end
+
+@implementation OFNotInSetException
+- (const char*)cString
+{
+	if (string != NULL)
+		return string;
+
+	asprintf(&string, "The requested key is not in the set of type %s!",
+	    [class name]);
+
 	return string;
 }
 @end
 
 @implementation OFOpenFileFailedException

Index: tests/OFDictionary/OFDictionary.m
==================================================================
--- tests/OFDictionary/OFDictionary.m
+++ tests/OFDictionary/OFDictionary.m
@@ -16,14 +16,17 @@
 
 #import "OFAutoreleasePool.h"
 #import "OFDictionary.h"
 #import "OFConstString.h"
 #import "OFString.h"
+#import "OFExceptions.h"
 
 int
 main()
 {
+	BOOL caught;
+
 	OFDictionary *dict = [OFDictionary dictionaryWithHashSize: 16];
 
 	OFAutoreleasePool *pool = [OFAutoreleasePool new];
 	OFString *key1 = [OFString stringWithCString: "key1"];
 	OFString *key2 = [OFString stringWithCString: "key2"];
@@ -35,17 +38,40 @@
 	[dict set: key2
 	       to: value2];
 	[pool release];
 
 	if (strcmp([[dict get: @"key1"] cString], "value1")) {
-		puts("\033[K\033[1;31mTest 1/2 failed!\033[m");
+		puts("\033[K\033[1;31mTest 1/4 failed!\033[m");
 		return 1;
 	}
 
 	if (strcmp([[dict get: key2] cString], "value2")) {
-		puts("\033[K\033[1;31mTest 2/2 failed!\033[m");
+		puts("\033[K\033[1;31mTest 2/4 failed!\033[m");
+		return 1;
+	}
+
+	caught = NO;
+	@try {
+		[dict get: @"key3"];
+	} @catch (OFNotInSetException *e) {
+		caught = YES;
+	}
+	if (!caught) {
+		puts("\033[K\033[1;31mTest 3/4 failed!\033[m");
+		return 1;
+	}
+
+	[dict remove: @"key2"];
+	caught = NO;
+	@try {
+		[dict remove: @"key2"];
+	} @catch (OFNotInSetException *e) {
+		caught = YES;
+	}
+	if (!caught) {
+		puts("\033[K\033[1;31mTest 4/4 failed!\033[m");
 		return 1;
 	}
 
-	puts("\033[1;32mTests successful: 2/2\033[0m");
+	puts("\033[1;32mTests successful: 4/4\033[0m");
 	return 0;
 }