diff --git a/ptrlib/binary/encoding/ansi.py b/ptrlib/binary/encoding/ansi.py
index da8b8fa..28cfaef 100644
--- a/ptrlib/binary/encoding/ansi.py
+++ b/ptrlib/binary/encoding/ansi.py
@@ -14,12 +14,12 @@ def _escape_codes():
     codes['CSI_CURSOR_MOVE']   = re.compile(b'^\x1b\[([1-9]\d*);([1-9]\d*)[Hf]')
     codes['CSI_CURSOR_ROW']    = re.compile(b'^\x1b\[([1-9]\d*)d')
     codes['CSI_CURSOR_COLUMN'] = re.compile(b'^\x1b\[([1-9]\d*)[`G]')
-    codes['CSI_CURSOR_UP']    = re.compile(b'^\x1b\[(\d+)A')
-    codes['CSI_CURSOR_DOWN']  = re.compile(b'^\x1b\[(\d+)B')
-    codes['CSI_CURSOR_RIGHT'] = re.compile(b'^\x1b\[(\d+)C')
-    codes['CSI_CURSOR_LEFT']  = re.compile(b'^\x1b\[(\d+)D')
-    codes['CSI_CURSOR_UP_HEAD']   = re.compile(b'^\x1b\[(\d+)F')
-    codes['CSI_CURSOR_DOWN_HEAD'] = re.compile(b'^\x1b\[(\d+)E')
+    codes['CSI_CURSOR_UP']    = re.compile(b'^\x1b\[(\d*)A')
+    codes['CSI_CURSOR_DOWN']  = re.compile(b'^\x1b\[(\d*)B')
+    codes['CSI_CURSOR_RIGHT'] = re.compile(b'^\x1b\[(\d*)C')
+    codes['CSI_CURSOR_LEFT']  = re.compile(b'^\x1b\[(\d*)D')
+    codes['CSI_CURSOR_UP_HEAD']   = re.compile(b'^\x1b\[(\d*)F')
+    codes['CSI_CURSOR_DOWN_HEAD'] = re.compile(b'^\x1b\[(\d*)E')
     codes['CSI_CURSOR_SAVE']    = re.compile(b'^\x1b\[s')
     codes['CSI_CURSOR_RESTORE'] = re.compile(b'^\x1b\[u')
     codes['CSI_CURSOR_REQUEST'] = re.compile(b'^\x1b\[6n')
@@ -87,17 +87,17 @@ def draw_ansi(buf: bytes):
         elif m := E['CSI_CURSOR_COLUMN'].match(buf):
             x = int(m.group(1)) - 1
         elif m := E['CSI_CURSOR_UP'].match(buf):
-            y = max(0, y - int(m.group(1)))
+            y = max(0, y - int(m.group(1))) if m.group(1) else max(0, y-1)
         elif m := E['CSI_CURSOR_DOWN'].match(buf):
-            y += int(m.group(1))
+            y += int(m.group(1)) if m.group(1) else 1
         elif m := E['CSI_CURSOR_LEFT'].match(buf):
-            x = max(0, x - int(m.group(1)))
+            x = max(0, x - int(m.group(1))) if m.group(1) else max(0, x-1)
         elif m := E['CSI_CURSOR_RIGHT'].match(buf):
-            x += int(m.group(1))
+            x += int(m.group(1)) if m.group(1) else 1
         elif m := E['CSI_CURSOR_UP_HEAD'].match(buf):
-            x, y = 0, max(0, y - int(m.group(1)))
+            x, y = 0, max(0, y - int(m.group(1))) if m.group(1) else max(0, y-1)
         elif m := E['CSI_CURSOR_DOWN_HEAD'].match(buf):
-            x, y = 0, y + int(m.group(1))
+            x, y = 0, y + int(m.group(1)) if m.group(1) else y+1
         elif m := E['CSI_CURSOR_SAVE'].match(buf):
             saved_sco = (x, y)
         elif m := E['CSI_CURSOR_RESTORE'].match(buf):