Prepare for next development interaction 0.4.0.dev1
diff --git a/Makefile b/Makefile
index c44b01e..dddf927 100644
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,7 @@
 
 .PHONY: help clean clean-dist build dev test system-test test-travis release pip-release bin-release dev-binder .binder-image audit audit-licenses
 
-BASE_VERSION?=0.3.0
+BASE_VERSION?=0.4.0.dev1
 VERSION=$(BASE_VERSION)-incubating
 COMMIT=$(shell git rev-parse --short=12 --verify HEAD)
 ifeq (, $(findstring dev, $(VERSION)))