diff --git a/Docker/lofar-base/Dockerfile.tmpl b/Docker/lofar-base/Dockerfile.tmpl
index 96b70375c3b043bc97ad86d5bb1a3b218cb998e9..a228d6defa6e28ecf0a18e60593dd5d3554fd7e1 100644
--- a/Docker/lofar-base/Dockerfile.tmpl
+++ b/Docker/lofar-base/Dockerfile.tmpl
@@ -31,7 +31,7 @@ ENV UID=${BUILD_UID}
 #
 # set-build-options
 #
-ENV J=4
+ENV J=6
 
 #
 # Base and runtime dependencies