diff --git a/.gitignore b/.gitignore
index 73c2c28..f68392a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@ cmake-build-release
 CMakeCache\.txt
 pc/frnetlib.pc
 include/frnetlib/version.h
+build
diff --git a/ext/gtest/CMakeLists.txt b/ext/gtest/CMakeLists.txt
index 6e94450..be751fa 100644
--- a/ext/gtest/CMakeLists.txt
+++ b/ext/gtest/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 2.8.8)
+cmake_minimum_required(VERSION 3.9)
 project(gtest_builder C CXX)
 include(ExternalProject)