diff --git a/build-macos.sh b/build-macos.sh
index b9b9ea9..6a3f9cb 100755
--- a/build-macos.sh
+++ b/build-macos.sh
@@ -7,7 +7,16 @@ for patch in ../*.patch; do
   patch -N -p1 -i "$patch"
 done
 export CFLAGS="-arch arm64 -arch x86_64 -mmacosx-version-min=10.11"
-./configure --target=powerpc-eabi --prefix="$PREFIX" --disable-nls --disable-shared --disable-gprof --without-zstd
-make -j$(nproc) configure-host
-make -j$(nproc)
+if command -v nproc >/dev/null 2>&1; then
+  JOBS="$(nproc)"
+else
+  JOBS="$(getconf _NPROCESSORS_ONLN 2>/dev/null || sysctl -n hw.ncpu 2>/dev/null || echo 4)"
+fi
+case "$JOBS" in
+  ''|*[!0-9]*) JOBS=4 ;;
+esac
+
+./configure --target=powerpc-eabi --prefix="$PREFIX" --disable-nls --disable-shared --disable-gprof --without-zstd --with-system-zlib
+make -j"$JOBS" configure-host
+make -j"$JOBS"
 make install-strip