diff --git a/ChangeLog.md b/ChangeLog.md
index 18bd8769..4dfa3f09 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,6 +1,15 @@
 Emperor ChangeLog
 =================
 
+# Emperor 1.0.4-dev (changes since 1.0.4 go here)
+
+### Bug Fixes
+
+### New Features
+
+### Miscellaneous
+
+
 # Emperor 1.0.4 (10 Jul 2023)
 -----------------------------
 
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 8271e168..f141567d 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -58,10 +58,10 @@
 # built documents.
 #
 # The short X.Y version.
-version = '1.0.4'
+version = '1.0.4-dev'
 
 # The full version, including alpha/beta/rc tags.
-release = '1.0.4'
+release = '1.0.4-dev'
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/setup.py b/setup.py
index ce3ecc2a..6292d392 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@
 
 from setuptools import setup, find_packages
 
-__version__ = "1.0.4"
+__version__ = "1.0.4-dev"
 __maintainer__ = "Emperor development team"
 __email__ = "yoshiki89@gmail.com"