diff --git a/aegisub/build/libaegisub_vs2008/libaegisub_vs2008.vcproj b/aegisub/build/libaegisub_vs2008/libaegisub_vs2008.vcproj
index 2da974d34..ca206a97d 100644
--- a/aegisub/build/libaegisub_vs2008/libaegisub_vs2008.vcproj
+++ b/aegisub/build/libaegisub_vs2008/libaegisub_vs2008.vcproj
@@ -205,6 +205,10 @@
 				RelativePath="..\..\libaegisub\common\option.cpp"
 				>
 			</File>
+			<File
+				RelativePath="..\..\libaegisub\common\option_value.cpp"
+				>
+			</File>
 			<File
 				RelativePath="..\..\libaegisub\common\option_visit.cpp"
 				>
diff --git a/aegisub/libaegisub/Makefile.am b/aegisub/libaegisub/Makefile.am
index 15a160a26..415962123 100644
--- a/aegisub/libaegisub/Makefile.am
+++ b/aegisub/libaegisub/Makefile.am
@@ -24,6 +24,7 @@ libaegisub_2_2_la_SOURCES = \
 	common/charset_ucd.cpp \
 	common/mru.cpp \
 	common/option.cpp \
+	common/option_value.cpp \
 	common/option_visit.cpp \
 	common/log.cpp \
 	common/validator.cpp \
diff --git a/aegisub/libaegisub/common/option_value.cpp b/aegisub/libaegisub/common/option_value.cpp
new file mode 100644
index 000000000..ac1a828de
--- /dev/null
+++ b/aegisub/libaegisub/common/option_value.cpp
@@ -0,0 +1,41 @@
+// Copyright (c) 2010, Niels M Hansen <nielsm@aegisub.org>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+// $Id$
+
+/// @file option_value.cpp
+/// @brief Container for holding an actual option value.
+/// @ingroup libaegisub
+
+#include "libaegisub/option_value.h"
+
+namespace agi {
+
+void OptionValue::NotifyChanged() {
+	for (ChangeListenerSet::const_iterator nfcb = listeners.begin(); nfcb != listeners.end(); ++nfcb) {
+		nfcb->first->*(nfcb->second);
+	}
+}
+
+void OptionValue::Subscribe(OptionValueListener *listener, OptionValueListener::ChangeEvent function) {
+	assert(listeners.find(listener) == listeners.end());
+	listeners[listener] = function;
+}
+
+void OptionValue::Unsubscribe(OptionValueListener *listener, OptionValueListener::ChangeEvent function) {
+	assert(listeners.find(listener) != listeners.end() && listeners[listener] == function);
+	listeners.erase(listener);
+}
+
+};
diff --git a/aegisub/libaegisub/include/libaegisub/option_value.h b/aegisub/libaegisub/include/libaegisub/option_value.h
index 06aa063b4..0266a9b91 100644
--- a/aegisub/libaegisub/include/libaegisub/option_value.h
+++ b/aegisub/libaegisub/include/libaegisub/option_value.h
@@ -20,6 +20,7 @@
 
 #ifndef LAGI_PRE
 #include <fstream>
+#include <map>
 #include <stdint.h>
 
 #include "libaegisub/cajun/reader.h"
@@ -48,16 +49,16 @@ class ConfigVisitor;
 /// signature.
 class OptionValueListener {
 public:
-	// (I might have messed up the syntax here. It's supposed to be a pointer
-	// to a member function of an OptionValueListener-derived class.)
-	typedef void (OptionValueListener::*ChangeEvent)(const OptionValue *option);
+	/// @brief Type of a notification callback function for option value changes
+	typedef void (OptionValueListener::*ChangeEvent)(const OptionValue &option);
 };
 
 
 /// @class OptionValue
 /// Holds an actual option.
 class OptionValue {
-	std::set<OptionValueListener*> listeners;
+	typedef std::map<OptionValueListener*, OptionValueListener::ChangeEvent> ChangeListenerSet;
+	ChangeListenerSet listeners;
 
 protected:
 	void NotifyChanged();
@@ -125,11 +126,8 @@ public:
 	virtual void GetDefaultListBool(std::vector<bool> &out) const { throw OptionValueErrorInvalidListType("Attempt to retrive string bool from non-bool list"); }
 
 
-	void Subscribe(OptionValueListener*);
-	void Unsubscribe(OptionValueListener*);
-
-	void Subscribe(OptionValueListener *listener, OptionValueListener::ChangeEvent handler);
-	void Unsubscribe(OptionValueListener *listener, OptionValueListener::ChangeEvent handler);
+	void Subscribe(OptionValueListener *listener, OptionValueListener::ChangeEvent function);
+	void Unsubscribe(OptionValueListener *listener, OptionValueListener::ChangeEvent function);
 
 };
 
@@ -142,11 +140,11 @@ public:
 		OptionValue##type_name(std::string member_name, type member_value):                   \
 						  value(member_value), name(member_name) {}                           \
 		type Get##type_name() const { return value; }                                         \
-		void Set##type_name(const type new_val) { value = new_val; }                          \
+		void Set##type_name(const type new_val) { value = new_val; NotifyChanged(); }         \
 		type GetDefault##type_name() const { return value_default; }                          \
 		OptionType GetType() const { return OptionValue::Type_##type_name; }                  \
 		std::string GetName() const { return name; }                                          \
-		void Reset() { value = value_default; }                                               \
+		void Reset() { value = value_default; NotifyChanged(); }                              \
 		bool IsDefault() const { return (value == value_default) ? 1 : 0; }                   \
 	};
 
@@ -181,11 +179,11 @@ protected:
 	virtual std::string GetString() const { return "";}                                       \
 		OptionValueList##type_name(std::string member_name): name(member_name) {}             \
 		void GetList##type_name(std::vector<type> &out) const { out = array; }                \
-		void SetList##type_name(const std::vector<type> val) { array = val;}                  \
+		void SetList##type_name(const std::vector<type> val) { array = val;  NotifyChanged(); } \
 		void GetDefaultList##type_name(std::vector<type> &out) const { out = array_default; } \
 		OptionType GetType() const { return OptionValue::Type_List_##type_name; }             \
 		std::string GetName() const { return name; }                                          \
-		void Reset() { array = array_default; }                                               \
+		void Reset() { array = array_default; NotifyChanged(); }                              \
 		bool IsDefault() const { return (array == array_default) ? 1 : 0; }                   \
 	};