--- portage/eclass/qt5-build.eclass
+++ portage/eclass/qt5-build.eclass
@@ -185,10 +185,12 @@ qt5-build_src_prepare() {
 		fi
 
 		# Respect CC, CXX, *FLAGS, MAKEOPTS and EXTRA_EMAKE when bootstrapping qmake
-		sed -i -e "/outpath\/qmake\".*\"\$MAKE\")/ s:): \
-			${MAKEOPTS} ${EXTRA_EMAKE} 'CC=$(tc-getCC)' 'CXX=$(tc-getCXX)' \
-			'QMAKE_CFLAGS=${CFLAGS}' 'QMAKE_CXXFLAGS=${CXXFLAGS}' 'QMAKE_LFLAGS=${LDFLAGS}'&:" \
+		sed -i -e "/outpath\/qmake\".*\"\$MAKE\")/ s:): ${MAKEOPTS} ${EXTRA_EMAKE}&:" \
 			-e 's/\(setBootstrapVariable\s\+\|EXTRA_C\(XX\)\?FLAGS=.*\)QMAKE_C\(XX\)\?FLAGS_\(DEBUG\|RELEASE\).*/:/' \
+			-e "s|setBootstrapVariable\s+QMAKE_CC\s+C.*|echo 'CC = $(tc-getCC)' >> \"\$mkfile\"|" \
+			-e "s|setBootstrapVariable\s+QMAKE_CXX\s+C.*|echo 'CXX = $(tc-getCC)' >> \"\$mkfile\"|" \
+			-e "s|setBootstrapVariable\s+QMAKE_CXXFLAGS$|echo 'QMAKE_CXXFLAGS = ${CXXFLAGS}' >> \"\$mkfile\"|" \
+			-e "s|setBootstrapVariable\s+QMAKE_LFLAGS$|echo 'QMAKE_LFLAGS = ${LDFLAGS}' >> \"\$mkfile\"|" \
 			configure || die "sed failed (respect env for qmake build)"
 		sed -i -e '/^CPPFLAGS\s*=/ s/-g //' \
 			qmake/Makefile.unix || die "sed failed (CPPFLAGS for qmake build)"