Index: src/OFExceptions.m
==================================================================
--- src/OFExceptions.m
+++ src/OFExceptions.m
@@ -422,12 +422,11 @@
 {
 	self = [super initWithClass: class__];
 
 	req_size = size;
 
-	/* FIXME: We need something that works for subclasses as well */
-	if (class__ == [OFTCPSocket class])
+	if ([class__ isSubclassOfClass: [OFTCPSocket class]])
 		err = GET_SOCK_ERR;
 	else
 		err = GET_ERR;
 
 	return self;

Index: src/OFObject.h
==================================================================
--- src/OFObject.h
+++ src/OFObject.h
@@ -76,10 +76,17 @@
 /**
  * \return The name of the class as a C string
  */
 + (const char*)className;
 
+/**
+ * \param class_ The class which is checked for being a superclass
+ * \return A boolean whether the class class is a subclass of the specified
+ *	   class
+ */
++ (BOOL)isSubclassOfClass: (Class)class_;
+
 /**
  * Checks whether instances of the class respond to a given selector.
  *
  * \param selector The selector which should be checked for respondance
  * \return A boolean whether instances of the class respond to the specified

Index: src/OFObject.m
==================================================================
--- src/OFObject.m
+++ src/OFObject.m
@@ -99,10 +99,25 @@
 	return class_getName(self);
 #else
 	return class_get_class_name(self);
 #endif
 }
+
++ (BOOL)isSubclassOfClass: (Class)class
+{
+	Class iter;
+
+#ifdef OF_APPLE_RUNTIME
+	for (iter = self; iter != Nil; iter = class_getSuperclass(iter))
+#else
+	for (iter = self; iter != Nil; iter = class_get_super_class(iter))
+#endif
+		if (iter == class)
+			return YES;
+
+	return NO;
+}
 
 + (BOOL)instancesRespondToSelector: (SEL)selector
 {
 #ifdef OF_APPLE_RUNTIME
 	return class_respondsToSelector(self, selector);