diff --git a/SCons/Config/gnu b/SCons/Config/gnu
index e9b0b993..fac295b0 100644
--- a/SCons/Config/gnu
+++ b/SCons/Config/gnu
@@ -178,6 +178,36 @@ if conf.CheckRequirement('memset', 'char c[128] = "test";'):
 
 conf.Finish()
 
+#
+# Some platforms, like FreeBSD, require -pthread flag to be passed
+# instead of -lpthread.
+#
+
+def check_pthread(ctx):
+	ctx.Message('Checking for -pthread... ')
+
+	last_flags = ctx.env['LINKFLAGS']
+
+	ctx.env.Append(LINKFLAGS = '-pthread')
+
+	test = """
+		int __main() {
+			return 0;
+		}
+	"""
+
+	result = not ctx.TryLink(test, '.c')
+	ctx.Result(result)
+
+	ctx.env.Replace(LINKFLAGS = last_flags)
+
+	return result
+
+conf = defenv.Configure(custom_tests = { 'CheckPThread' : check_pthread })
+if conf.CheckPThread():
+	makensis_env.Append(LINKFLAGS = '-pthread')
+conf.Finish()
+
 ### return
 
 Return('stub_env makensis_env plugin_env util_env cp_util_env')
diff --git a/Source/SConscript b/Source/SConscript
index 54071757..ed58843f 100644
--- a/Source/SConscript
+++ b/Source/SConscript
@@ -48,7 +48,6 @@ zlib_files = Split("""
 libs = Split("""
 	gdi32
 	user32
-	version
 	pthread
 	stdc++
 	iconv
@@ -58,6 +57,11 @@ Import('env AddAvailableLibs')
 
 ##### Use available libraries
 
+if env['PLATFORM'] == 'win32':
+	# XXX will cause problems if makensis is cross compiled
+	# on freebsd, libversion.a exists and gives trouble if linked
+	libs += ['version']
+
 AddAvailableLibs(env, libs)
 
 ##### Configuration defines
diff --git a/Source/mmap.cpp b/Source/mmap.cpp
index c23626f5..c6c9951c 100644
--- a/Source/mmap.cpp
+++ b/Source/mmap.cpp
@@ -3,6 +3,7 @@
 #include <cstdio> // for f*
 #include <cassert> // for assert
 #ifndef _WIN32
+#  include <sys/types.h> // for freebsd
 #  include <sys/mman.h>
 #  include <sys/stat.h>
 #  include <fcntl.h>