diff -ru orig/CMakeLists.txt mod/CMakeLists.txt
--- orig/CMakeLists.txt	2023-07-05 18:25:57.000000000 +0200
+++ mod/CMakeLists.txt	2023-10-06 08:29:27.429624816 +0200
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
+cmake_minimum_required(VERSION 3.5)
 
 project(ZXing)
 
@@ -37,9 +37,6 @@
     set (CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
 endif()
 
-if (NOT CMAKE_CXX_STANDARD)
-    set (CMAKE_CXX_STANDARD 17)
-endif()
 if (NOT CMAKE_CXX_EXTENSIONS)
     set (CMAKE_CXX_EXTENSIONS OFF)
 endif()
diff -ru orig/core/CMakeLists.txt mod/core/CMakeLists.txt
--- orig/core/CMakeLists.txt	2023-07-05 18:25:57.000000000 +0200
+++ mod/core/CMakeLists.txt	2023-10-06 08:29:35.169666650 +0200
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
+cmake_minimum_required(VERSION 3.5)
 
 project (ZXing VERSION "2.1.0")
 set (ZXING_SONAME 3) # see https://github.com/zxing-cpp/zxing-cpp/issues/333
@@ -459,8 +459,6 @@
     )
 endif()
 
-target_compile_features(ZXing PUBLIC cxx_std_17)
-
 target_link_libraries (ZXing PRIVATE Threads::Threads)
 
 add_library(ZXing::ZXing ALIAS ZXing)