diff --git a/utils/jenkins-build.sh b/utils/jenkins-build.sh
index ea8a52040..c4f8bd7bb 100755
--- a/utils/jenkins-build.sh
+++ b/utils/jenkins-build.sh
@@ -302,8 +302,18 @@ fi
 
 # convert javascript parameters
 if [ "${BUILD_JS}" = "json" ];then
-    BUILD_MOZJS=NO
-    BUILD_JS=YES
+    case ${TARGET} in
+	"riscos")
+	    BUILD_MOZJS=NO
+	    BUILD_JS=YES
+	    ;;
+	*)
+	    BUILD_MOZJS=YES
+	    BUILD_JS=NO
+	;;
+
+    esac
+
 else
     BUILD_JS=NO
     BUILD_MOZJS=NO