diff --git a/vlib/v/ast/cflags.v b/vlib/v/ast/cflags.v
index 77b155592d..347f1919a0 100644
--- a/vlib/v/ast/cflags.v
+++ b/vlib/v/ast/cflags.v
@@ -18,7 +18,7 @@ fn (t &Table) has_cflag(flag cflag.CFlag) bool {
 // parse the flags to (ast.cflags) []CFlag
 // Note: clean up big time (joe-c)
 pub fn (mut t Table) parse_cflag(cflg string, mod string, ctimedefines []string) ?bool {
-	allowed_flags := ['framework', 'library', 'Wa', 'Wl', 'Wp', 'I', 'l', 'L']
+	allowed_flags := ['framework', 'library', 'Wa', 'Wl', 'Wp', 'I', 'l', 'L', 'D']
 	flag_orig := cflg.trim_space()
 	mut flag := flag_orig
 	if flag == '' {
diff --git a/vlib/v/ast/cflags_test.v b/vlib/v/ast/cflags_test.v
index a64fe8c32b..51e29c9267 100644
--- a/vlib/v/ast/cflags_test.v
+++ b/vlib/v/ast/cflags_test.v
@@ -20,6 +20,10 @@ fn test_parse_valid_cflags() {
 		make_flag('windows', '-l', 'gdi32'),
 		make_flag(no_os, '-l', 'mysqlclient'),
 		make_flag(no_os, no_name, '-test'),
+		make_flag('linux', '-I', '/usr/include/SDL2'),
+		make_flag('linux', '-D', '_REENTRANT'),
+		make_flag('linux', '-L', '/usr/lib/x86_64-linux-gnu'),
+		make_flag('linux', '-l', 'SDL2'),
 	]
 	parse_valid_flag(mut t, '-lmysqlclient')
 	parse_valid_flag(mut t, '-test')
@@ -29,6 +33,7 @@ fn test_parse_valid_cflags() {
 	parse_valid_flag(mut t, 'mingw -mwindows')
 	parse_valid_flag(mut t, 'solaris -L/opt/local/lib')
 	parse_valid_flag(mut t, 'windows -lgdi32')
+	parse_valid_flag(mut t, 'linux -I/usr/include/SDL2 -D_REENTRANT -L/usr/lib/x86_64-linux-gnu -lSDL2')
 	assert t.cflags.len == expected_flags.len
 	for f in expected_flags {
 		assert t.has_cflag(f)