diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5704c54b84..47b1bfe8b8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # Change Log
 
+## [1.38.9] - Development
+
 ## [1.38.8] - 2023-09-08
 
 ### Added
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1e8763d6c7..c255924fa4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 # MaterialX Version
 set(MATERIALX_MAJOR_VERSION 1)
 set(MATERIALX_MINOR_VERSION 38)
-set(MATERIALX_BUILD_VERSION 8)
+set(MATERIALX_BUILD_VERSION 9)
 set(MATERIALX_LIBRARY_VERSION ${MATERIALX_MAJOR_VERSION}.${MATERIALX_MINOR_VERSION}.${MATERIALX_BUILD_VERSION})
 
 # Cmake setup