diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4cfc7ed925..bbd2e01653 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -78,9 +78,9 @@ execute_process (
         COMMAND ${GIT_EXECUTABLE} log -1 --format='%aI'
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         RESULT_VARIABLE EXITCODE3
-        OUTPUT_VARIABLE COMMITDATE
+        OUTPUT_VARIABLE OPENMW_VERSION_COMMITDATE
         OUTPUT_STRIP_TRAILING_WHITESPACE)
-string(SUBSTRING ${COMMITDATE} 1 10 OPENMW_VERSION_COMMITDATE)
+string(SUBSTRING ${OPENMW_VERSION_COMMITDATE} 1 10 OPENMW_VERSION_COMMITDATE)
 
 # Macros
 include(OpenMWMacros)