diff --git a/cat_win/src/web/updatechecker.py b/cat_win/src/web/updatechecker.py
index 78c2936..5203a98 100644
--- a/cat_win/src/web/updatechecker.py
+++ b/cat_win/src/web/updatechecker.py
@@ -107,7 +107,7 @@ def only_alpha(_s: str) -> str:
         only alpha chars and 'z'
     """
     x = 'abcdefghijklmnopqrstuvwxyz'
-    return ''.join(filter(lambda c: c in x, _s.lower())) + 'z'
+    return ''.join(filter(lambda c: c in x, _s.lower()))
 
 
 def gen_version_tuples(_v: str, _w: str) -> tuple:
@@ -171,6 +171,9 @@ def new_version_available(current_version: str, latest_version: str) -> int:
         if c_alpha < l_alpha:
             status = STATUS_PRE_RELEASE_AVAILABLE
             break
+        if c_alpha > l_alpha and all(l.isdigit() for l in latest[i-1:]):
+            status = STATUS_STABLE_RELEASE_AVAILABLE
+            break
     if i < len(current):
         status *= -1
     return status
diff --git a/cat_win/tests/src/web/test_updatechecker.py b/cat_win/tests/src/web/test_updatechecker.py
index 43f5b95..160a9bb 100644
--- a/cat_win/tests/src/web/test_updatechecker.py
+++ b/cat_win/tests/src/web/test_updatechecker.py
@@ -49,6 +49,7 @@ def test_version_comparison_stable_release(self):
         self.assertEqual(updatechecker.new_version_available('1.0.12', '1.000.020'), 1)
         self.assertEqual(updatechecker.new_version_available('v1.0.0', 'v01.00.01'), 1)
         self.assertEqual(updatechecker.new_version_available('2.1.5a', '2.1.6'), 1)
+        self.assertEqual(updatechecker.new_version_available('2.1.6a', '2.1.6'), 1)
         self.assertEqual(updatechecker.new_version_available('v2.1b.5a', '2.1b.051'), 1)
 
     def test_version_comparison_pre_release(self):
@@ -62,6 +63,7 @@ def test_version_comparison_stable_release_unsafe(self):
         self.assertEqual(updatechecker.new_version_available('1.0.15', '1.1.9'), -1)
         self.assertEqual(updatechecker.new_version_available('1.0.9', 'v2.0.9'), -1)
         self.assertEqual(updatechecker.new_version_available('1.0.12', '1.001.0'), -1)
+        self.assertEqual(updatechecker.new_version_available('1.10a.0', '1.10.0'), -1)
         self.assertEqual(updatechecker.new_version_available('v1.0.0', 'v01.001.01'), -1)
         self.assertEqual(updatechecker.new_version_available('2.1.5a', '2.2.5'), -1)