diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2bee250
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+test/
+genc.txt
\ No newline at end of file
diff --git a/genc.py b/genc.py
index f0bc3c4..f4e98b0 100644
--- a/genc.py
+++ b/genc.py
@@ -2,7 +2,7 @@ import re
 import xml.etree.ElementTree as ET
 
 class OpCode:
-    OPCODE_REGEX = re.compile("[0-9a-fA-F][0-9a-fA-F]")
+    OPCODE_REGEX = re.compile("[0-9A-F][0-9A-F]")
 
     def __init__(self, ins, operand_encodings):
         self.x32m = ins.attrib["x32m"]