diff --git a/tools/buildbot/bootstrap.pl b/tools/buildbot/bootstrap.pl
index 79e5d29ec..3ccef58dc 100755
--- a/tools/buildbot/bootstrap.pl
+++ b/tools/buildbot/bootstrap.pl
@@ -61,7 +61,7 @@ if ($^O !~ /MSWin/) {
 my $conf_args = join(' ', @conf_argv);
 
 if ($argn > 0 && $^O !~ /MSWin/) {
-	$result = `CC=$ARGV[0] CXX=$ARGV[0] python ../build/configure.py $conf_args`;
+	$result = `CC=$ARGV[0] CXX=$ARGV[1] python ../build/configure.py $conf_args`;
 } else {
 	if ($^O =~ /MSWin/) {
 		$result = `C:\\Python27\\Python.exe ..\\build\\configure.py $conf_args`;
diff --git a/tools/buildbot/startbuild.pl b/tools/buildbot/startbuild.pl
index 712ae630d..3e4bf3b57 100755
--- a/tools/buildbot/startbuild.pl
+++ b/tools/buildbot/startbuild.pl
@@ -13,7 +13,7 @@ chdir('../../../OUTPUT');
 my $argn = $#ARGV + 1;
 if ($argn > 0) {
 	$ENV{CC} = $ARGV[0];
-	$ENV{CXX} = $ARGV[0];
+	$ENV{CXX} = $ARGV[1];
 }
 
 system("ambuild --no-color 2>&1");