diff --git a/CMakeLists.txt b/CMakeLists.txt
index e10d0ace..1e154f41 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,15 +1,11 @@
-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.12)
 
 project(pocketpy)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-if (${CMAKE_VERSION} VERSION_LESS "3.12.0") 
-    set(Python3_EXECUTABLE "python3")
-else()
-    find_package(Python3 COMPONENTS Interpreter)
-endif()
+find_package(Python3 COMPONENTS Interpreter)
 
 execute_process(
     COMMAND ${Python3_EXECUTABLE} prebuild.py
diff --git a/run_tests.sh b/run_tests.sh
index 6ce5f06e..d86170b4 100644
--- a/run_tests.sh
+++ b/run_tests.sh
@@ -1,6 +1,6 @@
 python3 prebuild.py
 SRC=$(find src/ -name "*.cpp")
-clang++ -std=c++17 --coverage -O1 -stdlib=libc++ -Wfatal-errors -o main src2/main.cpp $SRC -Iinclude
+clang++ -std=c++17 --coverage -O1 -stdlib=libc++ -Wfatal-errors -o main src2/main.cpp $SRC -Iinclude -DPK_ENABLE_OS=1
 python3 scripts/run_tests.py
 
 # if prev error exit
diff --git a/scripts/genstub.py b/scripts/genstub.py
index 0ce8aafa..6283d4d4 100644
--- a/scripts/genstub.py
+++ b/scripts/genstub.py
@@ -34,4 +34,4 @@ with open('src2/pocketpy_c.c', 'w') as f:
 #endif
             
 ''')
-    f.write('\n'.join(a))
\ No newline at end of file
+    f.write('\n'.join(a))