diff --git a/build/premake/extern_libs4.lua b/build/premake/extern_libs4.lua
index 75e9af40be..4ae473f4ce 100644
--- a/build/premake/extern_libs4.lua
+++ b/build/premake/extern_libs4.lua
@@ -252,15 +252,6 @@ extern_lib_defs = {
 			})
 		end,
 	},
-	boost_signals = {
-		link_settings = function()
-			add_default_links({
-				android_names = { "boost_signals-gcc-mt" },
-				unix_names = { os.findlib("boost_signals-mt") and "boost_signals-mt" or "boost_signals" },
-				osx_names = { "boost_signals-mt" },
-			})
-		end,
-	},
 	comsuppw = {
 		link_settings = function()
 			add_default_links({
diff --git a/build/premake/premake4.lua b/build/premake/premake4.lua
index 3a50f8bdaa..2c38c8c621 100644
--- a/build/premake/premake4.lua
+++ b/build/premake/premake4.lua
@@ -1107,7 +1107,6 @@ function setup_atlas_projects()
 
 	atlas_extern_libs = {
 		"boost",
-		"boost_signals",
 		"comsuppw",
 		--"ffmpeg", -- disabled for now because it causes too many build difficulties
 		"libxml2",
diff --git a/source/tools/atlas/AtlasUI/CustomControls/Windows/AtlasWindow.h b/source/tools/atlas/AtlasUI/CustomControls/Windows/AtlasWindow.h
index a2c64999cd..43ba6ce21d 100644
--- a/source/tools/atlas/AtlasUI/CustomControls/Windows/AtlasWindow.h
+++ b/source/tools/atlas/AtlasUI/CustomControls/Windows/AtlasWindow.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2013 Wildfire Games.
+/* Copyright (C) 2014 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -26,10 +26,10 @@
 #include "wx/filename.h"
 
 #include <boost/version.hpp>
-#if BOOST_VERSION >= 105400
+#if BOOST_VERSION >= 104000
 # include <boost/signals2/signal.hpp>
 #else
-# include <boost/signal.hpp>
+# error Atlas requires Boost 1.40 or later
 #endif
 
 class AtObj;
@@ -52,12 +52,7 @@ public:
 	};
 
 	AtlasWindow(wxWindow* parent, const wxString& title, const wxSize& size);
-
-#if BOOST_VERSION >= 105400
 	boost::signals2::signal<void ()> sig_FileSaved;
-#else
-	boost::signal<void ()> sig_FileSaved;
-#endif
 
 private:
 
diff --git a/source/tools/atlas/AtlasUI/General/Observable.h b/source/tools/atlas/AtlasUI/General/Observable.h
index 39147701f3..a78dbdc809 100644
--- a/source/tools/atlas/AtlasUI/General/Observable.h
+++ b/source/tools/atlas/AtlasUI/General/Observable.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2013 Wildfire Games.
+/* Copyright (C) 2014 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -39,17 +39,15 @@ variable_to_be_watched.NotifyObservers();
 
 */
 
+#include <boost/bind.hpp>
 #include <boost/version.hpp>
-#if BOOST_VERSION >= 105400
+#if BOOST_VERSION >= 104000
 # include <boost/signals2.hpp>
 typedef boost::signals2::connection ObservableConnection;
 typedef boost::signals2::scoped_connection ObservableScopedConnection;
 #else
-# include <boost/signals.hpp>
-typedef boost::signals::connection ObservableConnection;
-typedef boost::signals::scoped_connection ObservableScopedConnection;
+# error Atlas requires Boost 1.40 or later
 #endif
-#include <boost/bind.hpp>
 
 template <typename T> class Observable : public T
 {
@@ -96,15 +94,8 @@ public:
 		else
 		{
 			// Temporarily disable conn
-#if BOOST_VERSION >= 105400
 			boost::signals2::shared_connection_block blocker(conn);
-#else
-			conn.block();
-#endif
 			NotifyObservers();
-#if BOOST_VERSION < 105400
-			conn.unblock();
-#endif
 		}
 	}
 
@@ -115,11 +106,7 @@ public:
 	}
 
 private:
-#if BOOST_VERSION >= 105400
 	boost::signals2::signal<void (const T&)> m_Signal;
-#else
-	boost::signal<void (const T&)> m_Signal;
-#endif
 };
 
 // A similar thing, but for wrapping pointers instead of objects
@@ -179,25 +166,14 @@ public:
 		else
 		{
 			// Temporarily disable conn
-#if BOOST_VERSION >= 105400
 			boost::signals2::shared_connection_block blocker(conn);
-#else
-			conn.block();
-#endif
 			NotifyObservers();
-#if BOOST_VERSION < 105400
-			conn.unblock();
-#endif
 		}
 	}
 
 private:
 	T* m_Ptr;
-#if BOOST_VERSION >= 105400
 	boost::signals2::signal<void (T*)> m_Signal;
-#else
-	boost::signal<void (T*)> m_Signal;
-#endif
 };
 
 class ObservableScopedConnections
diff --git a/source/tools/atlas/AtlasUI/Misc/precompiled.h b/source/tools/atlas/AtlasUI/Misc/precompiled.h
index 0c205bf77f..5863e2df7b 100644
--- a/source/tools/atlas/AtlasUI/Misc/precompiled.h
+++ b/source/tools/atlas/AtlasUI/Misc/precompiled.h
@@ -84,14 +84,13 @@
 #include <limits>
 #include <cassert>
 
+#include <boost/bind.hpp>
 #include <boost/version.hpp>
-#if BOOST_VERSION >= 105400
-// Signals is deprecated since 1.54
+#if BOOST_VERSION >= 104000
 # include <boost/signals2.hpp>
 #else
-# include <boost/signals.hpp> 
+# error Atlas requires Boost 1.40 or later
 #endif
-#include <boost/bind.hpp>
 
 // Nicer memory-leak detection:
 #ifdef _WIN32