diff --git a/vlib/v/table/atypes.v b/vlib/v/table/atypes.v
index 5970b044f4..e92d7d7f00 100644
--- a/vlib/v/table/atypes.v
+++ b/vlib/v/table/atypes.v
@@ -76,7 +76,7 @@ pub fn (t Type) set_nr_muls(nr_muls int) Type {
 	if nr_muls < 0 || nr_muls > 255 {
 		panic('set_nr_muls: nr_muls must be between 0 & 255')
 	}
-	return (((int(t) >> 24) & 0xff) << 24) | (nr_muls << 16) | (u16(t) & 0xffff)
+	return int(t) & 0xff00ffff | (nr_muls << 16)
 }
 
 // increments nr_nuls on `t` and return it
@@ -86,7 +86,8 @@ pub fn (t Type) to_ptr() Type {
 	if nr_muls == 255 {
 		panic('to_ptr: nr_muls is already at max of 255')
 	}
-	return (((int(t) >> 24) & 0xff) << 24) | ((nr_muls + 1) << 16) | (u16(t) & 0xffff)
+
+	return int(t) & 0xff00ffff | ((nr_muls + 1) << 16)
 }
 
 // decrement nr_muls on `t` and return it
@@ -96,37 +97,37 @@ pub fn (t Type) deref() Type {
 	if nr_muls == 0 {
 		panic('deref: type `$t` is not a pointer')
 	}
-	return (((int(t) >> 24) & 0xff) << 24) | ((nr_muls - 1) << 16) | (u16(t) & 0xffff)
+	return int(t) & 0xff00ffff | ((nr_muls - 1) << 16)
 }
 
 // set `flag` on `t` and return `t`
 [inline]
 pub fn (t Type) set_flag(flag TypeFlag) Type {
-	return ((((int(t) >> 24) & 0xff) | 1 << int(flag)) << 24) | (((int(t) >> 16) & 0xff) << 16) | (u16(t) & 0xffff)
+  return int(t) | (1 << (int(flag) + 24))
 }
 
 // clear `flag` on `t` and return `t`
 [inline]
 pub fn (t Type) clear_flag(flag TypeFlag) Type {
-	return ((((int(t) >> 24) & 0xff) & ~(1 << int(flag))) << 24) | (((int(t) >> 16) & 0xff) << 16) | (u16(t) & 0xffff)
+  return int(t) & ~(1 << (int(flag) + 24))
 }
 
 // clear all flags
 [inline]
 pub fn (t Type) clear_flags() Type {
-	return 0 | (((int(t) >> 16) & 0xff) << 16) | (u16(t) & 0xffff)
+	return int(t) & 0xffffff
 }
 
 // return true if `flag` is set on `t`
 [inline]
 pub fn (t Type) has_flag(flag TypeFlag) bool {
-	return (((int(t) >> 24) & 0xff) >> int(flag)) & 1 == 1
+  return int(t) & (1 << (int(flag) + 24)) > 0
 }
 
 // copy flags & nr_muls from `t_from` to `t` and return `t`
 [inline]
 pub fn (t Type) derive(t_from Type) Type {
-	return (((int(t_from) >> 24) & 0xff) << 24) | (((int(t_from) >> 16) & 0xff) << 16) | (u16(t) & 0xffff)
+	return (0xffff0000 & t_from) | u16(t)
 }
 
 // return new type with TypeSymbol idx set to `idx`
diff --git a/vlib/v/table/atypes_test.v b/vlib/v/table/atypes_test.v
new file mode 100644
index 0000000000..2034a62bfc
--- /dev/null
+++ b/vlib/v/table/atypes_test.v
@@ -0,0 +1,102 @@
+import table
+
+fn test_idx() {
+  mut t := table.new_type(table.void_type_idx)
+	assert t.idx() == table.void_type_idx
+
+  t = table.new_type(table.i8_type_idx)
+	assert t.idx() == table.i8_type_idx
+}
+
+fn test_muls() {
+  mut t := table.new_type(table.void_type_idx)
+
+  idx := t.idx()
+
+	assert t.nr_muls() == 0
+
+	for i in 0..32 {
+		t = t.set_nr_muls(i)
+		assert t.nr_muls() == i
+	}
+
+	t = t.set_nr_muls(0)
+	assert t.nr_muls() == 0
+	assert t.is_ptr() == false
+
+	t = t.to_ptr()
+	assert t.nr_muls() == 1
+	assert t.is_ptr() == true
+
+	t = t.to_ptr()
+	assert t.nr_muls() == 2
+	assert t.is_ptr() == true
+
+	t = t.deref()
+	assert t.nr_muls() == 1
+	assert t.is_ptr() == true
+
+	t = t.deref()
+	assert t.nr_muls() == 0
+	assert t.is_ptr() == false
+
+	assert t.idx() == idx
+}
+
+fn test_flags() {
+  mut t := table.new_type(table.void_type_idx)
+
+  idx := t.idx()
+  nr_muls := t.nr_muls()
+
+  t = t.set_flag(table.TypeFlag.optional)
+  assert t.has_flag(table.TypeFlag.optional) == true
+  assert t.has_flag(table.TypeFlag.variadic) == false
+  assert t.has_flag(table.TypeFlag.generic) == false
+
+  t = t.set_flag(table.TypeFlag.variadic)
+  assert t.has_flag(table.TypeFlag.optional) == true
+  assert t.has_flag(table.TypeFlag.variadic) == true
+  assert t.has_flag(table.TypeFlag.generic) == false
+
+  t = t.set_flag(table.TypeFlag.generic)
+  assert t.has_flag(table.TypeFlag.optional) == true
+  assert t.has_flag(table.TypeFlag.variadic) == true
+  assert t.has_flag(table.TypeFlag.generic) == true
+
+  assert t.idx() == idx
+  assert t.nr_muls() == nr_muls
+
+  t = t.clear_flag(table.TypeFlag.optional)
+  assert t.has_flag(table.TypeFlag.optional) == false
+  assert t.has_flag(table.TypeFlag.variadic) == true
+  assert t.has_flag(table.TypeFlag.generic) == true
+
+  t = t.clear_flag(table.TypeFlag.variadic)
+  assert t.has_flag(table.TypeFlag.optional) == false
+  assert t.has_flag(table.TypeFlag.variadic) == false
+  assert t.has_flag(table.TypeFlag.generic) == true
+
+  t = t.clear_flag(table.TypeFlag.generic)
+  assert t.has_flag(table.TypeFlag.optional) == false
+  assert t.has_flag(table.TypeFlag.variadic) == false
+  assert t.has_flag(table.TypeFlag.generic) == false
+
+  assert t.idx() == idx
+  assert t.nr_muls() == nr_muls
+}
+
+fn test_derive() {
+  mut t := table.new_type(table.i8_type_idx)
+  t = t.set_flag(table.TypeFlag.generic)
+  t = t.set_flag(table.TypeFlag.variadic)
+	t = t.set_nr_muls(10)
+
+  mut t2 := table.new_type(table.i16_type_idx)
+	t2 = t2.derive(t)
+  assert t2.has_flag(table.TypeFlag.optional) == false
+  assert t2.has_flag(table.TypeFlag.variadic) == true
+  assert t2.has_flag(table.TypeFlag.generic) == true
+  assert t2.nr_muls() == 10
+
+}