diff --git a/CMakeLists.txt b/CMakeLists.txt
index 21bd911a..53f63de3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12)
+cmake_minimum_required(VERSION 3.5)
 project(omohaaded)
 
 include(TargetArch.cmake)
@@ -24,7 +24,7 @@ endif()
 set(TARGET_BASE_GAME "main${TARGET_BASE_SUFFIX}")
 
 if(MSVC)
-	add_compile_definitions(_CRT_SECURE_NO_WARNINGS _CRT_NONSTDC_NO_DEPRECATE)
+	add_definitions(-D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE)
 elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
 	add_compile_options(-Wno-comment)
 	# Ignore warnings for code like 'assert("Assert string")'
@@ -57,7 +57,7 @@ ENDIF()
 
 IF(CMAKE_BUILD_TYPE MATCHES Debug)
 	set(TARGET_CONFIG_SUFFIX "-dbg")
-	add_compile_definitions(_DEBUG)
+	add_definitions(-D_DEBUG)
 ELSE()
 	set(TARGET_CONFIG_SUFFIX "")
 ENDIF()
@@ -88,7 +88,6 @@ add_library(fgame SHARED ${SOURCES_GAME_LIB})
 target_compile_definitions(fgame PRIVATE GAME_DLL ARCHIVE_SUPPORTED TARGET_GAME_TYPE=${TARGET_GAME_TYPE})
 target_include_directories(fgame PUBLIC "code/qcommon" "code/script" "code/game")
 target_include_directories(fgame PRIVATE "code/parser")
-set_target_properties(fgame PROPERTIES CXX_STANDARD 11)
 target_compile_features(fgame PUBLIC cxx_std_11)
 
 set_target_properties(fgame PROPERTIES PREFIX "${TARGET_PLATFORM_PREFIX}")
@@ -180,7 +179,6 @@ set(SOURCES_SERVER_APP ${SOURCES_APP} ${SOURCES_SERVER})
 add_executable(omohaaded ${SOURCES_SERVER_APP} ${SOURCES_PLATFORM_SPECIFIC} "code/null/null_client.c" "code/null/null_input.c" "code/null/null_snddma.c")
 target_compile_definitions(omohaaded PRIVATE NO_SCRIPTENGINE DEDICATED TARGET_GAME_TYPE=${TARGET_GAME_TYPE})
 target_compile_features(omohaaded PUBLIC cxx_std_11)
-set_target_properties(omohaaded PROPERTIES CXX_STANDARD 11)
 # Gamespy dependency
 add_dependencies(omohaaded gcd)
 target_link_libraries(omohaaded PRIVATE gcd)
diff --git a/code/gamespy/gcd.cmake b/code/gamespy/gcd.cmake
index 894237d7..4e666c71 100644
--- a/code/gamespy/gcd.cmake
+++ b/code/gamespy/gcd.cmake
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.12)
+cmake_minimum_required(VERSION 3.5)
 
 project(gcd)
 
@@ -80,7 +80,7 @@ add_library(gcd INTERFACE)
 set_property(TARGET gcd_common gcd_key PROPERTY POSITION_INDEPENDENT_CODE ON)
 
 if(UNIX)
-	add_compile_definitions(_LINUX=1)
+	add_definitions(-D_LINUX=1)
 endif(UNIX)
 
 set(DEPENDENT_LIBS