diff --git a/vlib/v/ast/cflags.v b/vlib/v/ast/cflags.v
index fac0a771a0..79c86b91e5 100644
--- a/vlib/v/ast/cflags.v
+++ b/vlib/v/ast/cflags.v
@@ -4,6 +4,7 @@
 module ast
 
 import v.cflag
+import v.checker.constants
 
 // check if cflag is in table
 pub fn (t &Table) has_cflag(flag cflag.CFlag) bool {
@@ -25,8 +26,8 @@ pub fn (mut t Table) parse_cflag(cflg string, mod string, ctimedefines []string)
 		return error('flag is empty')
 	}
 	mut fos := ''
-	mut allowed_os_overrides := ['linux', 'darwin', 'freebsd', 'openbsd', 'windows', 'mingw',
-		'solaris', 'android', 'termux']
+	mut allowed_os_overrides := []string{}
+	allowed_os_overrides << constants.valid_comptime_not_user_defined
 	allowed_os_overrides << ctimedefines
 	for os_override in allowed_os_overrides {
 		if !flag.starts_with(os_override) {
diff --git a/vlib/v/checker/constants/constants.v b/vlib/v/checker/constants/constants.v
index 6a248231c4..b50c1158d4 100644
--- a/vlib/v/checker/constants/constants.v
+++ b/vlib/v/checker/constants/constants.v
@@ -10,7 +10,7 @@ pub const (
 	valid_comptime_if_cpu_features   = ['x64', 'x32', 'little_endian', 'big_endian']
 	valid_comptime_if_other          = ['apk', 'js', 'debug', 'prod', 'test', 'glibc', 'prealloc',
 		'no_bounds_checking', 'freestanding', 'threads', 'js_node', 'js_browser', 'js_freestanding',
-		'interpreter', 'es5', 'profile', 'wasm32_emscripten']
+		'interpreter', 'es5', 'profile', 'wasm32', 'wasm32_emscripten', 'wasm32_wasi']
 	valid_comptime_not_user_defined  = all_valid_comptime_idents()
 )