diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7831c219c9..100fba4276 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,7 +19,7 @@ endif()
 
 # option() honors normal variables.
 if(POLICY CMP0077)
-	cmake_policy(SET CMP0077 NEW)
+  cmake_policy(SET CMP0077 NEW)
 endif()
 
 # SWIG: use standard target name.