diff --git a/vlib/builtin/utf8.c.v b/vlib/builtin/utf8.c.v
new file mode 100644
index 0000000000..04b25caf66
--- /dev/null
+++ b/vlib/builtin/utf8.c.v
@@ -0,0 +1,74 @@
+module builtin
+
+pub fn (_str string) to_wide() &u16 {
+	$if windows {
+		num_chars := (C.MultiByteToWideChar(cp_utf8, 0, charptr(_str.str), _str.len, 0, 0))
+		mut wstr := &u16(malloc((num_chars + 1) * 2)) // sizeof(wchar_t)
+		if wstr != 0 {
+			C.MultiByteToWideChar(cp_utf8, 0, charptr(_str.str), _str.len, wstr, num_chars)
+			unsafe {
+				C.memset(&byte(wstr) + num_chars * 2, 0, 2)
+			}
+		}
+		return wstr
+	} $else {
+		return 0
+	}
+}
+
+pub fn string_from_wide(_wstr &u16) string {
+	$if windows {
+		wstr_len := C.wcslen(_wstr)
+		return string_from_wide2(_wstr, wstr_len)
+	} $else {
+		return ''
+	}
+}
+
+pub fn string_from_wide2(_wstr &u16, len int) string {
+	$if windows {
+		num_chars := C.WideCharToMultiByte(cp_utf8, 0, _wstr, len, 0, 0, 0, 0)
+		mut str_to := malloc(num_chars + 1)
+		if str_to != 0 {
+			C.WideCharToMultiByte(cp_utf8, 0, _wstr, len, charptr(str_to), num_chars, 0, 0)
+			unsafe {
+				C.memset(str_to + num_chars, 0, 1)
+			}
+		}
+		return tos2(str_to)
+	} $else {
+		return ''
+	}
+}
+
+// Reads an utf8 character from standard input
+pub fn utf8_getchar() int {
+	c := C.getchar()
+	len := utf8_len(byte(~c))
+	if c < 0 {
+		return 0
+	}
+	else if len == 0 {
+		return c
+	}
+	else if len == 1 {
+		return -1
+	}
+	else {
+		mut uc := c & ((1<<(7 - len)) - 1)
+		for i := 0; i + 1 < len; i++ {
+			c2 := C.getchar()
+			if c2 != -1 && (c2>>6) == 2 {
+				uc <<= 6
+				uc |= (c2 & 63)
+			}
+			else if c2 == -1 {
+				return 0
+			}
+			else {
+				return -1
+			}
+		}
+		return uc
+	}
+}
diff --git a/vlib/builtin/utf8.v b/vlib/builtin/utf8.v
index 16ea26463b..1a2d66d900 100644
--- a/vlib/builtin/utf8.v
+++ b/vlib/builtin/utf8.v
@@ -70,51 +70,6 @@ pub fn (_rune string) utf32_code() int {
 	return res
 }
 
-const (
-	cp_utf8 = 65001
-)
-
-pub fn (_str string) to_wide() &u16 {
-	$if windows {
-		num_chars := (C.MultiByteToWideChar(cp_utf8, 0, charptr(_str.str), _str.len, 0, 0))
-		mut wstr := &u16(malloc((num_chars + 1) * 2)) // sizeof(wchar_t)
-		if wstr != 0 {
-			C.MultiByteToWideChar(cp_utf8, 0, charptr(_str.str), _str.len, wstr, num_chars)
-			unsafe {
-				C.memset(&byte(wstr) + num_chars * 2, 0, 2)
-			}
-		}
-		return wstr
-	} $else {
-		return 0
-	}
-}
-
-pub fn string_from_wide(_wstr &u16) string {
-	$if windows {
-		wstr_len := C.wcslen(_wstr)
-		return string_from_wide2(_wstr, wstr_len)
-	} $else {
-		return ''
-	}
-}
-
-pub fn string_from_wide2(_wstr &u16, len int) string {
-	$if windows {
-		num_chars := C.WideCharToMultiByte(cp_utf8, 0, _wstr, len, 0, 0, 0, 0)
-		mut str_to := malloc(num_chars + 1)
-		if str_to != 0 {
-			C.WideCharToMultiByte(cp_utf8, 0, _wstr, len, charptr(str_to), num_chars, 0, 0)
-			unsafe {
-				C.memset(str_to + num_chars, 0, 1)
-			}
-		}
-		return tos2(str_to)
-	} $else {
-		return ''
-	}
-}
-
 // Calculate length to read from the first byte
 fn utf8_len(c byte) int {
 	mut b := 0
@@ -193,35 +148,3 @@ fn utf8_str_visible_length(s string) int {
 	}
 	return l
 }
-
-// Reads an utf8 character from standard input
-pub fn utf8_getchar() int {
-	c := C.getchar()
-	len := utf8_len(byte(~c))
-	if c < 0 {
-		return 0
-	}
-	else if len == 0 {
-		return c
-	}
-	else if len == 1 {
-		return -1
-	}
-	else {
-		mut uc := c & ((1<<(7 - len)) - 1)
-		for i := 0; i + 1 < len; i++ {
-			c2 := C.getchar()
-			if c2 != -1 && (c2>>6) == 2 {
-				uc <<= 6
-				uc |= (c2 & 63)
-			}
-			else if c2 == -1 {
-				return 0
-			}
-			else {
-				return -1
-			}
-		}
-		return uc
-	}
-}
diff --git a/vlib/math/bits/bits.v b/vlib/math/bits/bits.v
index b61504a64f..c8c6264629 100644
--- a/vlib/math/bits/bits.v
+++ b/vlib/math/bits/bits.v
@@ -24,8 +24,8 @@ const (
 
 const (
 	// save importing math mod just for these
-	max_u32 = u32(4294967295)
-	max_u64 = u64(18446744073709551615)
+	max_u32 = 4294967295
+	max_u64 = 18446744073709551615
 )
 
 // --- LeadingZeros ---
diff --git a/vlib/strconv/atoi.v b/vlib/strconv/atoi.v
index b20d5c2383..a9c3bdb2db 100644
--- a/vlib/strconv/atoi.v
+++ b/vlib/strconv/atoi.v
@@ -9,7 +9,7 @@ const (
 // int_size = 32 << (~u32(0) >> 63)
 // max_u64 = u64(u64(1 << 63) - 1)
 	int_size = 32
-	max_u64 = u64(C.UINT64_MAX)// as u64 // use this until we add support
+	max_u64 = 18446744073709551615 // as u64 // use this until we add support
 )
 
 pub fn byte_to_lower(c byte) byte {