diff --git a/CMakeLists.txt b/CMakeLists.txt
index 38567930eb..8d197242ad 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,6 +9,11 @@ if(POLICY CMP0074)
   cmake_policy(SET CMP0074 NEW)
 endif()
 
+if(POLICY CMP0077)
+  # enable variables set outside to override options
+  cmake_policy(SET CMP0077 NEW)
+endif()
+
 #######################################
 # Create project and include cmake
 # configuration files