diff --git a/rewritegcode.py b/rewritegcode.py
index 1ed07e1..0deda96 100644
--- a/rewritegcode.py
+++ b/rewritegcode.py
@@ -20,6 +20,16 @@ MINY = 200
 MAXY = 1000
 
 OOZA_HEADER_PATH = "ooza/config.g"
+NUMBER_RE = r"(\d*)?(\.)?(\d*)?"
+
+
+def get_number_re(prefix):
+    pattern = f"{prefix}{NUMBER_RE}"
+    return re.compile(pattern)
+
+
+X_RE = get_number_re("X")
+Y_RE = get_number_re("Y")
 
 
 @dataclass
@@ -31,14 +41,15 @@ class GCodeInfo:
 
 
 def get_xy(line):
-    xmatch = re.search(r"X(\d*\.\d*)", line)
-    ymatch = re.search(r"Y(\d*\.\d*)", line)
+    xval = yval = None
+    xmatch = X_RE.search(line)
+    ymatch = Y_RE.search(line)
 
-    if xmatch is None or ymatch is None:
-        return None, None
+    if xmatch is not None:
+        xval = float(xmatch.group().strip("X"))
+    if ymatch is not None:
+        yval = float(ymatch.group().strip("Y"))
 
-    xval = float(xmatch.group().strip("X"))
-    yval = float(ymatch.group().strip("Y"))
     return xval, yval
 
 
diff --git a/test_rewritegocde.py b/test_rewritegocde.py
new file mode 100644
index 0000000..4d43125
--- /dev/null
+++ b/test_rewritegocde.py
@@ -0,0 +1,23 @@
+import unittest
+
+from rewritegcode import get_xy
+
+
+class TestRewriteGcode(unittest.TestCase):
+    def test_get_xy(self):
+        cases = [
+            ("G1 X4.8 Y3.4", (4.8, 3.4)),
+            ("G1 X400.8", (400.8, None)),
+            ("G1 Y4.8", (None, 4.8)),
+            ("G1 X4 Y3", (4, 3)),
+            ("G1 X40.32 Y3", (40.32, 3)),
+            ("G1 X.32 Y3", (.32, 3)),
+        ]
+        for (line, expected) in cases:
+            with self.subTest(line=line, expected=expected):
+                actual = get_xy(line)
+                self.assertEqual(expected, actual)
+
+
+if __name__ == "__main__":
+    unittest.main()