diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -162,10 +162,7 @@ else()
 endif()
 
 # version number
-set(MAJOR_VERSION 0 CACHE INT "Program major version number.")
-set(MINOR_VERSION 8 CACHE INT "Program minor version number.")
-set(PATCH_VERSION 1 CACHE INT "Program patch version number.")
-set(VERSION_STRING "${MAJOR_VERSION}.${MINOR_VERSION}.${PATCH_VERSION}")
+set(VERSION_STRING "0.8.1" CACHE STRING "Program version number.")
 
 # get revision number from mercurial
 find_program(MERCURIAL hg)