--- a/Makefile
+++ b/Makefile
@@ -42,7 +42,7 @@
 
 ############################## TOOLCHAIN ###############################
 #
-CSC         = mcs -sdk:4.0
+CSC         = mcs
 CSFLAGS     = -nologo -warn:4 -codepage:utf8 -unsafe -warnaserror
 DEFINE      = TRACE
 COMMON_LIBS = System.dll System.Core.dll System.Data.dll System.Data.DataSetExtensions.dll System.Drawing.dll System.Xml.dll thirdparty/download/ICSharpCode.SharpZipLib.dll thirdparty/download/FuzzyLogicLibrary.dll thirdparty/download/Mono.Nat.dll thirdparty/download/MaxMind.Db.dll thirdparty/download/MaxMind.GeoIP2.dll thirdparty/download/Eluant.dll thirdparty/download/SmarIrc4net.dll