diff --git a/build.sh b/build.sh
index ad9ac307f..6a6190433 100755
--- a/build.sh
+++ b/build.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/bin/bash
 
 # 
 # KLayout Layout Viewer
@@ -44,6 +44,7 @@ RPATH=""
 MAKE_OPT=""
 
 CONFIG="release"
+BUILD_EXPERT=0
 
 # Check, whether build.sh is run from the top level folder
 if ! [ -e src ] || ! [ -e src/klayout.pro ]; then
@@ -75,6 +76,9 @@ while [ "$*" != "" ]; do
   -debug)
     CONFIG="debug"
     ;;
+  -expert)
+    BUILD_EXPERT=1
+    ;;
   -python)
     PYTHON="$1"
     shift
@@ -500,28 +504,53 @@ $QMAKE -v
 # Force a minimum rebuild because of version info
 touch $CURR_DIR/src/version/version.h
 
-qmake_cmd="$QMAKE $CURR_DIR/src/klayout.pro -recursive \
-  CONFIG+=$CONFIG \
-  RUBYLIBFILE=$RUBYLIBFILE \
-  RUBYINCLUDE=$RUBYINCLUDE \
-  RUBYINCLUDE2=$RUBYINCLUDE2 \
-  RUBYVERSIONCODE=$RUBYVERSIONCODE \
-  HAVE_RUBY=$HAVE_RUBY \
-  PYTHONLIBFILE=$PYTHONLIBFILE \
-  PYTHONINCLUDE=$PYTHONINCLUDE \
-  HAVE_PYTHON=$HAVE_PYTHON \
-  HAVE_QTBINDINGS=$HAVE_QTBINDINGS \
-  HAVE_64BIT_COORD=$HAVE_64BIT_COORD \
-  HAVE_QT5=$HAVE_QT5 \
-  PREFIX='$BIN' \
-  RPATH='$RPATH' \
-  KLAYOUT_VERSION=$KLAYOUT_VERSION \
-  KLAYOUT_VERSION_DATE=$KLAYOUT_VERSION_DATE \
-  KLAYOUT_VERSION_REV=$KLAYOUT_VERSION_REV \
-"
+qmake_options=(
+  -recursive
+  CONFIG+="$CONFIG"
+  RUBYLIBFILE="$RUBYLIBFILE"
+  RUBYINCLUDE="$RUBYINCLUDE"
+  RUBYINCLUDE2="$RUBYINCLUDE2"
+  RUBYVERSIONCODE="$RUBYVERSIONCODE"
+  HAVE_RUBY="$HAVE_RUBY"
+  PYTHONLIBFILE="$PYTHONLIBFILE"
+  PYTHONINCLUDE="$PYTHONINCLUDE"
+  HAVE_PYTHON="$HAVE_PYTHON"
+  HAVE_QTBINDINGS="$HAVE_QTBINDINGS"
+  HAVE_64BIT_COORD="$HAVE_64BIT_COORD"
+  HAVE_QT5="$HAVE_QT5"
+  PREFIX="$BIN"
+  RPATH="$RPATH"
+  KLAYOUT_VERSION="$KLAYOUT_VERSION"
+  KLAYOUT_VERSION_DATE="$KLAYOUT_VERSION_DATE"
+  KLAYOUT_VERSION_REV="$KLAYOUT_VERSION_REV"
+)
 
-echo $qmake_cmd
-$qmake_cmd
+if [ $BUILD_EXPERT = 1 ]; then
+  qmake_options+=(
+    QMAKE_AR="$AR cqs"
+    QMAKE_LINK_C="$CC"
+    QMAKE_LINK_C_SHLIB="$CC"
+    QMAKE_LINK="$CXX"
+    QMAKE_LINK_SHLIB="$CXX"
+    QMAKE_OBJCOPY="$OBJCOPY"
+    QMAKE_RANLIB=
+    QMAKE_STRIP=
+    QMAKE_CC="$CC"
+    QMAKE_CXX="$CXX"
+    QMAKE_CFLAGS="$CFLAGS"
+    QMAKE_CFLAGS_RELEASE=
+    QMAKE_CFLAGS_DEBUG=
+    QMAKE_CXXFLAGS="$CXXFLAGS"
+    QMAKE_CXXFLAGS_RELEASE=
+    QMAKE_CXXFLAGS_DEBUG=
+    QMAKE_LFLAGS="$LDFLAGS"
+    QMAKE_LFLAGS_RELEASE=
+    QMAKE_LFLAGS_DEBUG=
+  )
+fi
+
+echo $QMAKE "$CURR_DIR/src/klayout.pro" "${qmake_options[@]}"
+$QMAKE "$CURR_DIR/src/klayout.pro" "${qmake_options[@]}"
 
 cd $CURR_DIR
 echo ""