diff --git a/utils.py b/utils.py
index bf2e020..aa59f32 100644
--- a/utils.py
+++ b/utils.py
@@ -10,4 +10,5 @@ def guess_classname(code: str) -> str:
 
 
 def camel_to_snake(input: str) -> str:
-    return re.sub(r'(?<!^)(?=[A-Z])', '_', input).lower()
+    s1 = re.sub('(.)([A-Z][a-z]+)', r'\1_\2', input)
+    return re.sub('([a-z0-9])([A-Z])', r'\1_\2', s1).lower()
diff --git a/utils_test.py b/utils_test.py
index 81605e3..2744f6a 100644
--- a/utils_test.py
+++ b/utils_test.py
@@ -22,3 +22,8 @@ def test_camel_to_snake_edge_case(self):
 
     def test_camel_to_snake_happy_path_multiple_capitals(self):
         self.assertEqual(camel_to_snake("MyClassIsReallyCool"), "my_class_is_really_cool")
+
+    def test_camel_to_snake_with_acronyms(self):
+        self.assertEqual(camel_to_snake("HTTPRequest"), "http_request")
+        self.assertEqual(camel_to_snake("URLConverter"), "url_converter")
+        self.assertEqual(camel_to_snake("HTMLParser"), "html_parser")