diff --git a/Source/Project64/N64 System/Cheat Class.cpp b/Source/Project64/N64 System/Cheat Class.cpp
index ac0f923b7..ea0070448 100644
--- a/Source/Project64/N64 System/Cheat Class.cpp	
+++ b/Source/Project64/N64 System/Cheat Class.cpp	
@@ -15,21 +15,6 @@
 enum { WM_EDITCHEAT           = WM_USER + 0x120 };
 enum { UM_CHANGECODEEXTENSION = WM_USER + 0x121 };
 
-static int is_valid_hex_digit(char symbol)
-{
-    if (symbol <  '0')
-        return 0; /* no valid hex figures before '0' */
-    if (symbol <= '9')
-        return 1;
-
-    symbol &= ~('X' ^ 'x'); /* in ASCII, forces lowercase to uppercase */
-    if (symbol <  'A')
-        return 0;
-    if (symbol <= 'F')
-        return 1;
-    return 0;
-}
-
 CCheats::CCheats (const CN64Rom * Rom ) :
 	m_Rom(Rom),
 	m_rcList(new RECT),
@@ -1786,7 +1771,7 @@ stdstr CCheats::ReadCodeString (HWND hDlg, bool &validcodes, bool &validoptions,
 		if (len <= 0) { continue; }
 
 		for (i=0; i<128; i++) {
-			if (is_valid_hex_digit(str[i])) {
+			if (isxdigit(str[i])) {
 				tempformat[i] = 'X';
 			}
 			if ((str[i] == ' ') || (str[i] == '?')) {
@@ -1860,7 +1845,7 @@ stdstr CCheats::ReadOptionsString(HWND hDlg, bool &/*validcodes*/, bool &validop
 			case 1: //option = lower byte
 				if (len >= 2) {
 					for (i=0; i<2; i++) {
-						if (!is_valid_hex_digit(str[i])) {
+						if (!isxdigit(str[i])) {
 							validoptions = false;
 							break;
 						}
@@ -1893,7 +1878,7 @@ stdstr CCheats::ReadOptionsString(HWND hDlg, bool &/*validcodes*/, bool &validop
 			case 2: //option = word
 				if (len >= 4) {
 					for (i=0; i<4; i++) {
-						if (!is_valid_hex_digit(str[i])) {
+						if (!isxdigit(str[i])) {
 							validoptions = false;
 							break;
 						}