diff --git a/Docs/src/compiler.but b/Docs/src/compiler.but
index fd83b179..f1add194 100644
--- a/Docs/src/compiler.but
+++ b/Docs/src/compiler.but
@@ -203,6 +203,14 @@ Date & time of the last modification to the script file according to the current
 
 NSIS version used to build the script.
 
+\S1{prensispackedversion} $\{NSIS_PACKEDVERSION\}
+
+NSIS version as a 32 bit number.
+
+\c !if 0x2046000 >= ${NSIS_PACKEDVERSION}
+\c   !error "NSIS 2.47 or higher is required to build this installer!"
+\c !endif
+
 \S1{scopepredefines} Scope Predefines
 
 Standard predefines that contain information of the current code scope.
diff --git a/SConstruct b/SConstruct
index 2bb262d3..66c28000 100644
--- a/SConstruct
+++ b/SConstruct
@@ -142,8 +142,9 @@ Examples/gfx.nsi"""))
 opts.Add(('VERSION', 'Version of NSIS', cvs_version))
 opts.Add(('VER_MAJOR', 'Major version of NSIS (recommended for dist-installer)', None))
 opts.Add(('VER_MINOR', 'Minor version of NSIS (recommended for dist-installer)', None))
-opts.Add(('VER_REVISION', 'Revision of NSIS (recommended for dist-installer)', None))
-opts.Add(('VER_BUILD', 'Build version of NSIS (recommended for dist-installer)', None))
+opts.Add(('VER_REVISION', 'Revision of NSIS', None))
+opts.Add(('VER_BUILD', 'Build version of NSIS', None))
+opts.Add(('VER_PACKED', 'Packed version of NSIS in 0xMMmmmrrb format, used for feature detection in scripts (recommended if VER_MAJOR and VER_MINOR are not set)', None))
 # installation
 opts.Add(('PREFIX', 'Installation prefix', dirs['prefix']))
 opts.Add(ListVariable('SKIPSTUBS', 'A list of stubs that will not be built', 'none', stubs))
@@ -235,6 +236,16 @@ f = open(defenv.File('#$BUILD_CONFIG/nsis-version.h').abspath, 'w')
 f.write('// This file is automatically generated by SCons\n// DO NOT EDIT THIS FILE\n')
 f.write('#include "tchar.h"\n')
 
+if (not defenv.has_key('VER_PACKED')) and defenv.has_key('VER_MAJOR') and defenv.has_key('VER_MINOR'):
+	packed_r = packed_b = 0
+	if defenv.has_key('VER_REVISION'):
+		packed_r = int(defenv['VER_REVISION'])
+	if defenv.has_key('VER_BUILD'):
+		packed_r = int(defenv['VER_BUILD'])
+	defenv['VER_PACKED'] = '0x%0.2i%0.3i%0.2i%0.1i' % (int(defenv['VER_MAJOR']),int(defenv['VER_MINOR']),packed_r,packed_b)
+if defenv.has_key('VER_PACKED'):
+	f.write('#define NSIS_PACKEDVERSION _T("%s")\n' % defenv['VER_PACKED'])
+
 if defenv.has_key('VER_MAJOR'):
 	defenv['VERSION'] = defenv['VER_MAJOR']
 	if defenv.has_key('VER_MINOR'):
diff --git a/Source/build.cpp b/Source/build.cpp
index 5c23c1ca..6df36ae7 100644
--- a/Source/build.cpp
+++ b/Source/build.cpp
@@ -131,6 +131,9 @@ CEXEBuild::CEXEBuild() :
   ns_label.add(_T(""),0);
 
   definedlist.add(_T("NSIS_VERSION"), NSIS_VERSION);
+#ifdef NSIS_PACKEDVERSION
+  definedlist.add(_T("NSIS_PACKEDVERSION"), NSIS_PACKEDVERSION);
+#endif
 
   target_minimal_OS=0;
   build_unicode=false;