diff --git a/build-djgpp.sh b/build-djgpp.sh
index 398ed9a..980977d 100755
--- a/build-djgpp.sh
+++ b/build-djgpp.sh
@@ -239,7 +239,9 @@ if [ ! -z ${GCC_VERSION} ]; then
   cd djcross || exit 1
 
   TEMP_CFLAGS="$CFLAGS"
+  TEMP_CXXFLAGS="$CXXFLAGS"
   export CFLAGS="$CFLAGS $GCC_EXTRA_CFLAGS"
+  export CXXFLAGS="$CXXFLAGS $GCC_EXTRA_CXXFLAGS"
 
   GCC_CONFIGURE_OPTIONS+=" --target=${TARGET} --prefix=${PREFIX} ${HOST_FLAG} ${BUILD_FLAG}
                            --enable-languages=${ENABLE_LANGUAGES}"
@@ -260,7 +262,8 @@ if [ ! -z ${GCC_VERSION} ]; then
   echo "Installing gcc (stage 1)"
   ${SUDO} ${MAKE_J} install-gcc || exit 1
 
-  export CFLAGS="$TEMP_CFLAGS"
+  CFLAGS="$TEMP_CFLAGS"
+  CXXFLAGS="$TEMP_CXXFLAGS"
 fi
 
 if [ ! -z ${DJGPP_VERSION} ]; then
@@ -313,7 +316,10 @@ if [ ! -z ${GCC_VERSION} ]; then
   cd $BUILDDIR/djcross || exit 1
 
   TEMP_CFLAGS="$CFLAGS"
+  TEMP_CXXFLAGS="$CXXFLAGS"
   export CFLAGS="$CFLAGS $GCC_EXTRA_CFLAGS"
+  export CXXFLAGS="$CXXFLAGS $GCC_EXTRA_CXXFLAGS"
+
   export STAGE_CC_WRAPPER="${BASE}/script/destdir-hack.sh ${DST}/${TARGET}"
   ${MAKE_J} || exit 1
   [ ! -z $MAKE_CHECK_GCC ] && ${MAKE_J} -s check-gcc | tee ${BASE}/tests/gcc.log
@@ -321,7 +327,9 @@ if [ ! -z ${GCC_VERSION} ]; then
   ${SUDO} ${MAKE_J} install-strip || \
   ${SUDO} ${MAKE_J} install-strip || exit 1
   ${SUDO} ${MAKE_J} -C mpfr install DESTDIR=${BASE}/build/tmpinst
+
   CFLAGS="$TEMP_CFLAGS"
+  CXXFLAGS="$TEMP_CXXFLAGS"
 
   set_version gcc
 fi
diff --git a/script/build-avr-gcc.sh b/script/build-avr-gcc.sh
index b51abb7..3fd3de7 100644
--- a/script/build-avr-gcc.sh
+++ b/script/build-avr-gcc.sh
@@ -48,7 +48,9 @@ if [ ! -z ${GCC_VERSION} ]; then
   cd gcc-${GCC_VERSION}/build-${TARGET} || exit 1
 
   TEMP_CFLAGS="$CFLAGS"
+  TEMP_CXXFLAGS="$CXXFLAGS"
   export CFLAGS="$CFLAGS $GCC_EXTRA_CFLAGS"
+  export CXXFLAGS="$CXXFLAGS $GCC_EXTRA_CXXFLAGS"
 
   GCC_CONFIGURE_OPTIONS+=" --target=${TARGET} --prefix=${PREFIX} ${HOST_FLAG} ${BUILD_FLAG}
                            --enable-languages=${ENABLE_LANGUAGES}
@@ -69,7 +71,8 @@ if [ ! -z ${GCC_VERSION} ]; then
   echo "Installing gcc (stage 1)"
   ${SUDO} ${MAKE_J} install-gcc || exit 1
 
-  export CFLAGS="$TEMP_CFLAGS"
+  CFLAGS="$TEMP_CFLAGS"
+  CXXFLAGS="$TEMP_CXXFLAGS"
 fi
 
 cd ${BASE}/build/
@@ -103,6 +106,11 @@ if [ ! -z ${GCC_VERSION} ]; then
   echo "Building gcc (stage 2)"
   cd gcc-${GCC_VERSION}/build-${TARGET} || exit 1
 
+  TEMP_CFLAGS="$CFLAGS"
+  TEMP_CXXFLAGS="$CXXFLAGS"
+  export CFLAGS="$CFLAGS $GCC_EXTRA_CFLAGS"
+  export CXXFLAGS="$CXXFLAGS $GCC_EXTRA_CXXFLAGS"
+
   export STAGE_CC_WRAPPER="${BASE}/script/destdir-hack.sh ${DST}/${TARGET}"
   ${MAKE_J} || exit 1
   [ ! -z $MAKE_CHECK_GCC ] && ${MAKE_J} -s check-gcc | tee ${BASE}/tests/gcc.log
@@ -111,5 +119,8 @@ if [ ! -z ${GCC_VERSION} ]; then
   ${SUDO} ${MAKE_J} install-strip || exit 1
   ${SUDO} ${MAKE_J} -C mpfr install DESTDIR=${BASE}/build/tmpinst
 
+  CFLAGS="$TEMP_CFLAGS"
+  CXXFLAGS="$TEMP_CXXFLAGS"
+
   set_version gcc
 fi
diff --git a/script/build-newlib-gcc.sh b/script/build-newlib-gcc.sh
index 082c8ce..cc028bf 100644
--- a/script/build-newlib-gcc.sh
+++ b/script/build-newlib-gcc.sh
@@ -40,7 +40,9 @@ if [ ! -z ${GCC_VERSION} ]; then
   cd gcc-${GCC_VERSION}/build-${TARGET} || exit 1
 
   TEMP_CFLAGS="$CFLAGS"
+  TEMP_CXXFLAGS="$CXXFLAGS"
   export CFLAGS="$CFLAGS $GCC_EXTRA_CFLAGS"
+  export CXXFLAGS="$CXXFLAGS $GCC_EXTRA_CXXFLAGS"
 
   GCC_CONFIGURE_OPTIONS+=" --target=${TARGET} --prefix=${PREFIX} ${HOST_FLAG} ${BUILD_FLAG}
                            --enable-languages=${ENABLE_LANGUAGES}
@@ -61,7 +63,8 @@ if [ ! -z ${GCC_VERSION} ]; then
   echo "Installing gcc (stage 1)"
   ${SUDO} ${MAKE_J} install-gcc || exit 1
 
-  export CFLAGS="$TEMP_CFLAGS"
+  CFLAGS="$TEMP_CFLAGS"
+  CXXFLAGS="$TEMP_CXXFLAGS"
 fi
 
 cd ${BASE}/build/
@@ -96,7 +99,12 @@ if [ ! -z ${GCC_VERSION} ]; then
   echo "Building gcc (stage 2)"
   cd gcc-${GCC_VERSION}/build-${TARGET} || exit 1
 
+  TEMP_CFLAGS="$CFLAGS"
+  TEMP_CXXFLAGS="$CXXFLAGS"
+  export CFLAGS="$CFLAGS $GCC_EXTRA_CFLAGS"
+  export CXXFLAGS="$CXXFLAGS $GCC_EXTRA_CXXFLAGS"
   export STAGE_CC_WRAPPER="${BASE}/script/destdir-hack.sh ${DST}/${TARGET}"
+
   ${MAKE_J} || exit 1
   [ ! -z $MAKE_CHECK_GCC ] && ${MAKE_J} -s check-gcc | tee ${BASE}/tests/gcc.log
   echo "Installing gcc"
@@ -104,5 +112,8 @@ if [ ! -z ${GCC_VERSION} ]; then
   ${SUDO} ${MAKE_J} install-strip || exit 1
   ${SUDO} ${MAKE_J} -C mpfr install DESTDIR=${BASE}/build/tmpinst
 
+  CFLAGS="$TEMP_CFLAGS"
+  CXXFLAGS="$TEMP_CXXFLAGS"
+
   set_version gcc
 fi
diff --git a/script/init.sh b/script/init.sh
index 5e5cfcd..5c3eb13 100644
--- a/script/init.sh
+++ b/script/init.sh
@@ -63,8 +63,8 @@ MINGW*)
   # Make sure MSYS2 Perl is used on mingw-w64 (see issue #27)
   export PERL=/usr/bin/perl
   # Required to build gcc on recent mingw-w64 (see issue #41)
-  CFLAGS+=' -DWIN32_LEAN_AND_MEAN'
-  CXXFLAGS+=' -DWIN32_LEAN_AND_MEAN'
+  GCC_EXTRA_CFLAGS+=' -DWIN32_LEAN_AND_MEAN'
+  GCC_EXTRA_CXXFLAGS+=' -DWIN32_LEAN_AND_MEAN'
   ;;
 esac