diff --git a/scripts/build.sh b/scripts/build.sh
index d1f7b1fad..cf58b659a 100755
--- a/scripts/build.sh
+++ b/scripts/build.sh
@@ -136,7 +136,9 @@ echo Building in $SRC, installing in $INSTALL_ROOT
 if [ ! -z $CMAKE_PREFIX_PATH ] ; then
 	QMAKE=$CMAKE_PREFIX_PATH/../../bin/qmake
 else
-	QMAKE=qmake
+	hash qmake > /dev/null && QMAKE=qmake
+	[ -z $QMAKE ] && hash qmake-qt5 > /dev/null && QMAKE=qmake-qt5
+	[ -z $QMAKE ] && echo "cannot find qmake" && exit 1
 fi
 
 # on Debian and Ubuntu based systems, the private QtLocation and