diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 154e3850e..d40aa0b33 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -1,3 +1,8 @@
+# Release 4.0 - (Not released yet; release notes are incomplete)
+
+ * Lightning Network
+ * Http PayServer can be configured from GUI
+
 # Release 3.3.8 - (July 11, 2019)
 
  * fix some bugs with recent bump fee (RBF) improvements (#5483, #5502)
diff --git a/electrum/version.py b/electrum/version.py
index 9a047f214..1d2c0bb56 100644
--- a/electrum/version.py
+++ b/electrum/version.py
@@ -1,5 +1,5 @@
-ELECTRUM_VERSION = '3.3.8'   # version of the client package
-APK_VERSION = '3.3.8.0'      # read by buildozer.spec
+ELECTRUM_VERSION = '4.0.0a0' # version of the client package
+APK_VERSION = '4.0.0.0'      # read by buildozer.spec
 
 PROTOCOL_VERSION = '1.4'     # protocol version requested