diff --git a/waflib/Configure.py b/waflib/Configure.py
index 88468d23..3448f05c 100644
--- a/waflib/Configure.py
+++ b/waflib/Configure.py
@@ -208,17 +208,17 @@ class ConfigurationContext(Context.Context):
 		"""
 		if not env.PREFIX:
 			if Options.options.prefix or Utils.is_win32:
-				env.PREFIX = os.path.abspath(os.path.expanduser(Options.options.prefix))
+				env.PREFIX = Utils.sane_path(Options.options.prefix)
 			else:
 				env.PREFIX = ''
 		if not env.BINDIR:
 			if Options.options.bindir:
-				env.BINDIR = os.path.abspath(os.path.expanduser(Options.options.bindir))
+				env.BINDIR = Utils.sane_path(Options.options.bindir)
 			else:
 				env.BINDIR = Utils.subst_vars('${PREFIX}/bin', env)
 		if not env.LIBDIR:
 			if Options.options.libdir:
-				env.LIBDIR = os.path.abspath(os.path.expanduser(Options.options.libdir))
+				env.LIBDIR = Utils.sane_path(Options.options.libdir)
 			else:
 				env.LIBDIR = Utils.subst_vars('${PREFIX}/lib%s' % Utils.lib64(), env)
 
@@ -529,7 +529,6 @@ def find_binary(self, filenames, exts, paths):
 						return x
 	return None
 
-
 @conf
 def run_build(self, *k, **kw):
 	"""
diff --git a/waflib/Options.py b/waflib/Options.py
index f11fe3e3..fe2121e3 100644
--- a/waflib/Options.py
+++ b/waflib/Options.py
@@ -256,7 +256,7 @@ class OptionsContext(Context.Context):
 				commands.append(arg)
 
 		if options.destdir:
-			options.destdir = os.path.abspath(os.path.expanduser(options.destdir))
+			options.destdir = Utils.sane_path(options.destdir)
 
 		if options.verbose >= 1:
 			self.load('errcheck')
diff --git a/waflib/Scripting.py b/waflib/Scripting.py
index 832e3573..cb9feebd 100644
--- a/waflib/Scripting.py
+++ b/waflib/Scripting.py
@@ -46,6 +46,7 @@ def waf_entry_point(current_directory, version, wafdir):
 		# perhaps extract 'wscript' as a constant
 		if os.path.basename(potential_wscript) == 'wscript' and os.path.isfile(potential_wscript):
 			# need to explicitly normalize the path, as it may contain extra '/.'
+			# TODO abspath?
 			current_directory = os.path.normpath(os.path.dirname(potential_wscript))
 			sys.argv.pop(1)
 
@@ -62,11 +63,14 @@ def waf_entry_point(current_directory, version, wafdir):
 					break
 
 	# if --top is provided assume the build started in the top directory
-	for x in sys.argv:
+	for i, x in enumerate(sys.argv):
+		# WARNING: this modifies sys.argv
 		if x.startswith('--top='):
-			Context.run_dir = Context.top_dir = x[6:]
+			Context.run_dir = Context.top_dir = Utils.sane_path(x[6:])
+			sys.argv[i] = '--top=' + Context.run_dir
 		if x.startswith('--out='):
-			Context.out_dir = x[6:]
+			Context.out_dir = Utils.sane_path(x[6:])
+			sys.argv[i] = '--out=' + Context.out_dir
 
 	# try to find a lock file (if the project was configured)
 	# at the same time, store the first wscript file seen
diff --git a/waflib/Utils.py b/waflib/Utils.py
index e00221d6..9ebaa2f8 100644
--- a/waflib/Utils.py
+++ b/waflib/Utils.py
@@ -753,3 +753,7 @@ def lib64():
 				return '64'
 	return ''
 
+def sane_path(p):
+	# private function for the time being!
+	return os.path.abspath(os.path.expanduser(p))
+