diff --git a/Toolchain/BuildIt.sh b/Toolchain/BuildIt.sh
index faf16e72d2..365ac4e2d5 100755
--- a/Toolchain/BuildIt.sh
+++ b/Toolchain/BuildIt.sh
@@ -93,8 +93,8 @@ pushd "$DIR/Build/"
         make install-gcc install-target-libgcc || exit 1
 
         echo "XXX serenity libc and libm"
-        ( cd "$DIR/../Libraries/LibC/" && ./install.sh )
-        ( cd "$DIR/../Libraries/LibM/" && ./install.sh )
+        ( cd "$DIR/../Libraries/LibC/" && make clean && make && ./install.sh )
+        ( cd "$DIR/../Libraries/LibM/" && make clean && make && ./install.sh )
 
         echo "XXX build libstdc++"
         make all-target-libstdc++-v3 || exit 1