--- qt5-build.eclass.orig	2018-02-22 20:38:52.000000000 +0100
+++ qt5-build.eclass	2018-02-25 06:44:07.449217175 +0100
@@ -122,7 +122,7 @@ case ${QT5_BUILD_TYPE} in
 	release) : ${QT5_BUILD_DIR:=${S}} ;; # workaround for bug 497312
 esac
 
-IUSE="debug test"
+IUSE="cpu_flags_x86_sse2 debug test"
 
 [[ ${PN} == qtwebkit ]] && RESTRICT+=" mirror" # bug 524584
 [[ ${QT5_BUILD_TYPE} == release ]] && RESTRICT+=" test" # bug 457182
@@ -588,6 +588,9 @@ qt5_base_configure() {
 		$(is-flagq -mno-dsp   && echo -no-mips_dsp)
 		$(is-flagq -mno-dspr2 && echo -no-mips_dspr2)
 
+		# Check for availability of SSE2 and switch off if necessary
+		$(use cpu_flags_x86_sse2 || echo -no-sse2)
+		
 		# use pkg-config to detect include and library paths
 		-pkg-config