diff --git a/setup.py b/setup.py
index 395a48f6..7aebac23 100644
--- a/setup.py
+++ b/setup.py
@@ -135,7 +135,7 @@ def build_isa_l():
 
 setup(
     name="isal",
-    version="1.4.0",
+    version="1.5.0-dev",
     description="Faster zlib and gzip compatible compression and "
                 "decompression by providing python bindings for the ISA-L "
                 "library.",
diff --git a/src/isal/__init__.py b/src/isal/__init__.py
index df9230ee..64ba0dbb 100644
--- a/src/isal/__init__.py
+++ b/src/isal/__init__.py
@@ -27,4 +27,4 @@
     "__version__"
 ]
 
-__version__ = "1.4.0"
+__version__ = "1.5.0-dev"