@@ -151,10 +151,24 @@
 - (size_t)requestedSize
 {
 	return req_size;
 }
 @end
+
+@implementation OFEnumerationMutationException
+- (OFString*)string
+{
+	if (string != nil)
+		return string;
+
+	string = [[OFString alloc] initWithFormat:
+	    @"Object of class %s was mutated during enumeration!",
+	    [class_ className]];
+
+	return string;
+}
+@end
 
 @implementation OFMemoryNotPartOfObjectException
 + newWithClass: (Class)class__
        pointer: (void*)ptr
 {