diff --git a/CMakeLists.txt b/CMakeLists.txt
index a877e9a7..bf093167 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,7 +14,7 @@ endif()
 
 # Imath version
 
-project(Imath VERSION 3.1.4 LANGUAGES C CXX)
+project(Imath VERSION 3.1.5 LANGUAGES C CXX)
 
 set(IMATH_VERSION_RELEASE_TYPE "" CACHE STRING "Extra version tag string for Imath build, such as -dev, -beta1, etc.")
 
@@ -39,7 +39,7 @@ set(IMATH_VERSION_API "${Imath_VERSION_MAJOR}_${Imath_VERSION_MINOR}")
 #   3. API changed:   CURRENT+1.0.0
 #
 set(IMATH_LIBTOOL_CURRENT 29)
-set(IMATH_LIBTOOL_REVISION 3)
+set(IMATH_LIBTOOL_REVISION 4)
 set(IMATH_LIBTOOL_AGE 0)
 set(IMATH_LIB_VERSION "${IMATH_LIBTOOL_CURRENT}.${IMATH_LIBTOOL_REVISION}.${IMATH_LIBTOOL_AGE}")
 set(IMATH_LIB_SOVERSION ${IMATH_LIBTOOL_CURRENT})