Addressed upstream: https://github.com/LASzip/LASzip/pull/129
--- CMakeLists.txt.orig	2025-12-08 17:36:04
+++ CMakeLists.txt	2026-02-05 09:30:43
@@ -1,20 +1,28 @@
 cmake_minimum_required(VERSION 3.10)
 
 project(LASZIP CXX C)
-set(CMAKE_CXX_STANDARD 17)
+
 string(TOLOWER ${PROJECT_NAME} PROJECT_NAME_LOWER)
 
 set(ROOT_DIR "${PROJECT_SOURCE_DIR}")
 
+if (NOT CMAKE_CXX_STANDARD)
+    set(CMAKE_CXX_STANDARD 17)
+    set(CMAKE_CXX_STANDARD_REQUIRED ON)
+endif()
+
+if (NOT CMAKE_C_STANDARD)
+    set(CMAKE_C_STANDARD 99)
+    set(CMAKE_C_STANDARD_REQUIRED ON)
+endif()
+
 if (MSVC)
   add_compile_options("/std:c++17")
-else()
-  add_compile_options(-std=c++17)
 endif()
 
 if(CMAKE_GNU_COMPILER_ID OR CMAKE_Clang_COMPILER_ID)
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wno-format-security -Wno-format-truncation")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-format-security -Wno-format-truncation -std=c++17")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-format-security -Wno-format-truncation")
 endif()
 
 # the next line is the ONLY place in the entire laszip system where
--- cmake/unix_compiler_options.cmake.orig	2025-12-08 17:36:04
+++ cmake/unix_compiler_options.cmake	2026-02-05 10:03:46
@@ -2,21 +2,15 @@
 )
 
 if (${CMAKE_CXX_COMPILER_ID} MATCHES "GNU")
-    if (${CMAKE_CXX_COMPILER_VERSION} VERSION_LESS 4.7)
-       set(CXX_STANDARD "-std=c++0x")
-    else()
-       set(CXX_STANDARD "-std=c++11")
-    endif()
     if (${CMAKE_CXX_COMPILER_VERSION} VERSION_GREATER 4.6)
         set(LASZIP_NO_AS_NEEDED_START "-Wl,--no-as-needed")
         set(LASZIP_NO_AS_NEEDED_END "-Wl,--as-needed")
     endif()
     set(LASZIP_COMPILER_GCC 1)
 elseif (${CMAKE_CXX_COMPILER_ID} MATCHES "Clang")
-    set(CXX_STANDARD "-std=c++11")
     set(LASZIP_COMPILER_CLANG 1)
 else()
     message(FATAL_ERROR "Unsupported C++ compiler")
 endif()
 
-set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${LASZIP_COMMON_CXX_FLAGS} ${CXX_STANDARD}")
+set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${LASZIP_COMMON_CXX_FLAGS}")