diff --git a/LFS/master.sh b/LFS/master.sh
index ba59c1e..562b55f 100644
--- a/LFS/master.sh
+++ b/LFS/master.sh
@@ -128,9 +128,12 @@ chapter_targets() {       #
 
       # If using optimizations, write the instructions
       case "${OPTIMIZE}$1${nb_chaps}${this_script}${REALSBU}" in
-          0* | *binutils-pass1y | 15* | 167* | 177*) ;;
-          *kernel*) wrt_makeflags "$name" ;; # No CFLAGS for kernel
-          *) wrt_optimize "$name" && wrt_makeflags "$name" ;;
+          0* | *binutils-pass1y | 15* | 167* | 177*)
+              wrt_makeflags "$name" "-j1" "1" ;;
+          *kernel*) # No CFLAGS for kernel
+              wrt_makeflags "$name" "$JH_MAKEFLAGS" "$N_PARALLEL" ;;
+          *)  wrt_optimize "$name" &&
+              wrt_makeflags "$name" "$JH_MAKEFLAGS" "$N_PARALLEL" ;;
       esac
     fi