diff --git a/vlib/v/gen/native/amd64.v b/vlib/v/gen/native/amd64.v
index e1ee3c8c1b..29e73895ca 100644
--- a/vlib/v/gen/native/amd64.v
+++ b/vlib/v/gen/native/amd64.v
@@ -1757,7 +1757,7 @@ fn (mut c Amd64) sar8(r Amd64Register, val u8) {
 pub fn (mut c Amd64) call_fn(node ast.CallExpr) {
 	name := node.name
 	mut n := name
-	if !n.contains('.') {
+	if !n.contains('.') && n !in c.g.fn_addr.keys() { // if the name is in keys, it is a function from builtin
 		n = 'main.${n}'
 	}
 	if node.is_method {
diff --git a/vlib/v/gen/native/blacklist.v b/vlib/v/gen/native/blacklist.v
index c2674b9ef6..b643724f71 100644
--- a/vlib/v/gen/native/blacklist.v
+++ b/vlib/v/gen/native/blacklist.v
@@ -29,7 +29,19 @@ already compiling functions:
 // false: whitelist function
 // true: blacklist function
 const whitelist = {
-	'main.main': false
+	'main.main':       false
+	'exit':            false
+	'gc_is_enabled':   false
+	'int_max':         false
+	'int_min':         false
+	'u8.is_alnum':     false
+	'u8.is_bin_digit': false
+	'u8.is_capital':   false
+	'u8.is_digit':     false
+	'u8.is_hex_digit': false
+	'u8.is_letter':    false
+	'u8.is_oct_digit': false
+	'u8.is_space':     false
 }
 
 fn (g &Gen) is_blacklisted(name string, is_builtin bool) bool {
diff --git a/vlib/v/gen/native/builtins.v b/vlib/v/gen/native/builtins.v
index 9f4196cf47..5b9fc76c54 100644
--- a/vlib/v/gen/native/builtins.v
+++ b/vlib/v/gen/native/builtins.v
@@ -19,7 +19,7 @@ mut:
 	calls []i64 // call addresses
 }
 
-pub const inline_builtins = ['assert', 'print', 'eprint', 'println', 'eprintln', 'exit', 'C.syscall'] // classic V builtin functions accessible to the user get inlined
+pub const inline_builtins = ['print', 'eprint', 'println', 'eprintln', 'C.syscall'] // classic V builtin functions accessible to the user get inlined
 
 pub fn (mut g Gen) init_builtins() {
 	g.builtins = {
diff --git a/vlib/v/gen/native/expr.v b/vlib/v/gen/native/expr.v
index 6d0c5cb25e..7cc73beb03 100644
--- a/vlib/v/gen/native/expr.v
+++ b/vlib/v/gen/native/expr.v
@@ -27,9 +27,6 @@ fn (mut g Gen) expr(node ast.Expr) {
 				'C.syscall' {
 					g.code_gen.gen_syscall(node)
 				}
-				'exit' {
-					g.code_gen.gen_exit(node.args[0].expr)
-				}
 				'println', 'print', 'eprintln', 'eprint' {
 					expr := node.args[0].expr
 					typ := node.args[0].typ
diff --git a/vlib/v/gen/native/gen.v b/vlib/v/gen/native/gen.v
index f88527ae34..8579937929 100644
--- a/vlib/v/gen/native/gen.v
+++ b/vlib/v/gen/native/gen.v
@@ -1174,6 +1174,7 @@ fn (mut g Gen) println(comment string) {
 
 @[noreturn]
 pub fn (mut g Gen) n_error(s string) {
+	print_backtrace()
 	util.verror('native error', s)
 }
 
diff --git a/vlib/v/gen/native/tests/builtin.vv b/vlib/v/gen/native/tests/builtin.vv
new file mode 100644
index 0000000000..b2fa2f71ad
--- /dev/null
+++ b/vlib/v/gen/native/tests/builtin.vv
@@ -0,0 +1,46 @@
+/* uncomment when floats are supported
+println(f32_abs(32.32))
+println(f32_abs(-32.32))
+println(f32_max(32.32, -32.32))
+println(f32_max(-32.32, 32.32))
+println(f32_min(32.32, -32.32))
+println(f32_min(-32.32, 32.32))
+println(f64_abs(32.32))
+println(f64_abs(-32.32))
+println(f64_max(32.32, -32.32))
+println(f64_max(-32.32, 32.32))
+println(f64_min(32.32, -32.32))
+println(f64_min(-32.32, 32.32))
+*/
+/* uncomment when C variables are working like C.stdout
+flush_stderr()
+flush_stdout()
+*/
+
+gc_is_enabled() // not yet enabled so only calling it 
+
+println(int_max(32, -32))
+println(int_max(-32, 32))
+println(int_min(32, -32))
+println(int_min(-32, 32))
+
+// print_character(`a`) enable when C vars will work
+
+assert u8(`a`).is_alnum()
+assert !u8(`_`).is_alnum()
+assert u8(`0`).is_bin_digit()
+assert !u8(`3`).is_bin_digit()
+assert u8(`A`).is_capital()
+assert !u8(`a`).is_capital()
+assert u8(`0`).is_digit()
+assert !u8(`a`).is_digit()
+assert u8(`A`).is_hex_digit()
+assert !u8(`G`).is_hex_digit()
+assert u8(`c`).is_letter()
+assert !u8(`2`).is_letter()
+assert u8(`7`).is_oct_digit()
+assert !u8(`8`).is_oct_digit()
+assert u8(` `).is_space()
+assert !u8(`_`).is_space()
+
+exit(0)
diff --git a/vlib/v/gen/native/tests/builtin.vv.out b/vlib/v/gen/native/tests/builtin.vv.out
new file mode 100644
index 0000000000..88ce05a04f
--- /dev/null
+++ b/vlib/v/gen/native/tests/builtin.vv.out
@@ -0,0 +1,4 @@
+32
+32
+-32
+-32