diff --git a/meson.build b/meson.build
index 71300d3..25bbf9f 100644
--- a/meson.build
+++ b/meson.build
@@ -1,9 +1,9 @@
 project('libzim', ['c', 'cpp'],
   version : '9.4.0',
   license : 'GPL2',
-  default_options : ['c_std=c11', 'cpp_std=c++17', 'werror=true'])
+  default_options : ['c_std=c11', 'cpp_std=c++17'])
 
-if build_machine.system() != 'windows'
+if host_machine.system() != 'windows' or meson.get_compiler('cpp').get_id() == 'gcc'
   add_project_arguments('-D_LARGEFILE64_SOURCE=1', '-D_FILE_OFFSET_BITS=64', language: 'cpp')
 endif
 
@@ -69,7 +69,7 @@ else
 endif
 
 compiler = meson.get_compiler('cpp')
-if (compiler.get_id() == 'gcc' and build_machine.system() == 'linux') or host_machine.system() == 'freebsd'
+if (compiler.get_id() == 'gcc' and host_machine.system() == 'linux') or host_machine.system() == 'freebsd'
   # C++ std::thread is implemented using pthread on linux by gcc
   thread_dep = dependency('threads')
 else