diff --git a/mp-build/scripts/mp-build.sh b/mp-build/scripts/mp-build.sh
index ead1bef..9610ba8 100755
--- a/mp-build/scripts/mp-build.sh
+++ b/mp-build/scripts/mp-build.sh
@@ -345,6 +345,7 @@ unset_indent
 
 info "Running the build function"
 export CC="gcc"
+export CXX="gcc"
 export CFLAGS="-march=x86-64 -mtune=generic -O2"
 export ROOTDIR="${rootpath}"
 export MAKEFLAGS="-j${OPT_CORES}"
@@ -364,7 +365,7 @@ else
 fi
 
 unset XORG_CONFIG XORG_PREFIX
-unset MAKEOPTS MAKEFLAGS
+unset MAKEOPTS MAKEFLAGS CXX
 unset CFLAGS ROOTDIR CC
 
 if [ "$SECONDS" != "0" ]; then