diff --git a/meson.build b/meson.build
index 9fc822ca0e..b5ceadc58f 100644
--- a/meson.build
+++ b/meson.build
@@ -800,7 +800,7 @@ endif
 
 libm = cc.find_library('m', required: false)
 
-if targetos == 'windows'
+if host_os == 'windows'
   threads = declare_dependency()
   meson.override_dependency('threads', threads)
 else
@@ -1935,7 +1935,7 @@ have_gtk_clipboard = get_option('gtk_clipboard').enabled()
 
 # xemu: GTK is required in Linux builds for file selection interfaces. In the
 # future, this may be relaxed in the future with alternative options.
-require_gtk = targetos == 'linux'
+require_gtk = host_os == 'linux'
 
 if require_gtk or get_option('gtk') \
              .disable_auto_if(not have_system) \
diff --git a/ui/meson.build b/ui/meson.build
index eace7858b7..6b0bd6cf3c 100644
--- a/ui/meson.build
+++ b/ui/meson.build
@@ -43,9 +43,13 @@ xemu_cocoa = dependency('appleframeworks', modules: 'Cocoa')
 xemu_ss.add(xemu_cocoa)
 endif
 
-xemu_ss.add(when: 'CONFIG_LINUX', if_true: [gtk, files('xemu-os-utils-linux.c')])
-xemu_ss.add(when: 'CONFIG_WIN32', if_true: files('xemu-os-utils-windows.c'))
-xemu_ss.add(when: 'CONFIG_DARWIN', if_true: files('xemu-os-utils-macos.m'))
+if host_os == 'linux'
+  xemu_ss.add([gtk, files('xemu-os-utils-linux.c')])
+elif host_os == 'windows'
+  xemu_ss.add(files('xemu-os-utils-windows.c'))
+elif host_os == 'darwin'
+  xemu_ss.add(files('xemu-os-utils-macos.m'))
+endif
 xemu_ss.add(imgui, implot, stb_image, noc, sdl, opengl, openssl, fa, fpng, json, httplib, fatx)
 system_ss.add_all(xemu_ss)
 
diff --git a/ui/thirdparty/meson.build b/ui/thirdparty/meson.build
index baa38cb771..c40caaad77 100644
--- a/ui/thirdparty/meson.build
+++ b/ui/thirdparty/meson.build
@@ -34,10 +34,14 @@ implot = declare_dependency(link_with: libimplot,
                             include_directories: 'implot')
 
 noc_ss = ss.source_set()
-noc_ss.add(when: 'CONFIG_LINUX', if_true: [gtk, files('noc_file_dialog/noc_file_dialog_gtk.c')])
-noc_ss.add(when: 'CONFIG_WIN32', if_true: files('noc_file_dialog/noc_file_dialog_win32.cc'))
-noc_ss.add(when: 'CONFIG_DARWIN', if_true: files('noc_file_dialog/noc_file_dialog_macos.m'))
-noc_ss = noc_ss.apply(config_all, strict: false)
+if host_os == 'linux'
+  noc_ss.add([gtk, files('noc_file_dialog/noc_file_dialog_gtk.c')])
+elif host_os == 'windows'
+  noc_ss.add(files('noc_file_dialog/noc_file_dialog_win32.cc'))
+elif host_os == 'darwin'
+  noc_ss.add(files('noc_file_dialog/noc_file_dialog_macos.m'))
+endif
+noc_ss = noc_ss.apply(config_target, strict: false)
 noclib = static_library('noc',
                         sources: noc_ss.sources(),
                         dependencies: noc_ss.dependencies(),
@@ -64,7 +68,7 @@ json = declare_dependency(include_directories: 'json')
 
 httplib_proj = subproject('cpp-httplib', default_options: ['cpp-httplib_openssl=enabled'])
 httplib_deps = [httplib_proj.get_variable('cpp_httplib_dep')]
-if targetos == 'windows'
+if host_os == 'windows'
   httplib_deps += [crypt32]
 endif
 httplib = declare_dependency(dependencies: httplib_deps)
diff --git a/ui/xui/meson.build b/ui/xui/meson.build
index 2fe5b2c64a..1f2f8d3aed 100644
--- a/ui/xui/meson.build
+++ b/ui/xui/meson.build
@@ -22,4 +22,6 @@ xemu_ss.add(files(
   'widgets.cc',
 ))
 
-xemu_ss.add(when: 'CONFIG_WIN32', if_true: files('update.cc'))
+if host_os == 'windows'
+  xemu_ss.add(files('update.cc'))
+endif
diff --git a/util/meson.build b/util/meson.build
index f7985a9bac..9b7056e8f9 100644
--- a/util/meson.build
+++ b/util/meson.build
@@ -64,7 +64,9 @@ util_ss.add(files('int128.c'))
 util_ss.add(files('memalign.c'))
 util_ss.add(files('interval-tree.c'))
 util_ss.add(files('lockcnt.c'))
-util_ss.add(when: 'CONFIG_WIN32', if_true: files('miniz/miniz.c'))
+if host_os == 'windows'
+  util_ss.add(files('miniz/miniz.c'))
+endif
 util_ss.add(files('fast-hash.c'))
 util_ss.add(files('mstring.c'))
 
diff --git a/winpcap-loader/meson.build b/winpcap-loader/meson.build
index 3c3265921f..715fc6c5b3 100644
--- a/winpcap-loader/meson.build
+++ b/winpcap-loader/meson.build
@@ -1,3 +1,3 @@
-softmmu_ss.add(when: 'CONFIG_WIN32', if_true: files(
-  'loader.c',
-))
+if host_os == 'windows'
+  system_ss.add('loader.c')
+endif