diff --git a/AUTHORS.rst b/AUTHORS.rst
index 6b44851..680a22e 100644
--- a/AUTHORS.rst
+++ b/AUTHORS.rst
@@ -5,6 +5,7 @@ reporting, all input is greatly appreciated!
 
 Code contributions:
 
+- Gary (gary1110086)
 - Alexandre Decan (AlexandreDecan)
 - dhilipsiva (dhilipsiva)
 - MAA (FooBarQuaxx)
diff --git a/CHANGES.rst b/CHANGES.rst
index c4a347d..1dadc02 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,6 +4,8 @@ Changelog
 Version 7.4.1
 -------------
 
+* Release converted attribute aliases when keys are deleted or popped.
+
 * Fixing #303 Wrong version number (7.3.3) in 7.4.0 release (thanks to Michał Górny)
 
 Version 7.4.0
diff --git a/box/box.py b/box/box.py
index 8252643..5c4b070 100644
--- a/box/box.py
+++ b/box/box.py
@@ -724,6 +724,11 @@ def __delitem__(self, key):
             super().__delitem__(key)
         except KeyError as err:
             raise BoxKeyError(str(err)) from _exception_cause(err)
+        if self._box_config["conversion_box"]:
+            safe_key = self._safe_attr(key)
+            safe_keys = self._box_config["__safe_keys"]
+            if safe_key in safe_keys and safe_keys[safe_key] == key:
+                del safe_keys[safe_key]
 
     def __delattr__(self, item):
         if self._box_config["frozen_box"]:
@@ -746,7 +751,6 @@ def __delattr__(self, item):
                 safe_key = self._safe_attr(item)
                 if safe_key in self._box_config["__safe_keys"]:
                     self.__delitem__(self._box_config["__safe_keys"][safe_key])
-                    del self._box_config["__safe_keys"][safe_key]
                     return
             raise BoxKeyError(str(err)) from _exception_cause(err)
 
diff --git a/test/test_box.py b/test/test_box.py
index e5c56e0..937ed1f 100644
--- a/test/test_box.py
+++ b/test/test_box.py
@@ -54,6 +54,37 @@ def temp_dir_cleanup(self):
         yield
         shutil.rmtree(str(tmp_dir), ignore_errors=True)
 
+    @pytest.mark.parametrize("removal", ["item", "attribute", "converted_attribute", "pop", "popitem"])
+    def test_removed_key_releases_conversion_alias(self, removal):
+        bx = Box({"a b": 1}, box_duplicates="error")
+        if removal == "item":
+            del bx["a b"]
+        elif removal == "attribute":
+            delattr(bx, "a b")
+        elif removal == "converted_attribute":
+            del bx.a_b
+        elif removal == "pop":
+            bx.pop("a b")
+        else:
+            bx.popitem()
+
+        bx["a-b"] = 2
+        assert bx.to_dict() == {"a-b": 2}
+        assert bx.a_b == 2
+        with pytest.raises(BoxError):
+            bx["a b"] = 3
+
+    def test_deleting_none_key_after_conversion_alias_owner(self):
+        bx = Box({None: 1, "None": 2})
+        del bx["None"]
+        del bx[None]
+        assert bx.to_dict() == {}
+
+    def test_deleting_colliding_key_keeps_other_conversion_alias(self):
+        bx = Box({"a b": 1, "a-b": 2})
+        del bx["a b"]
+        assert bx.a_b == 2
+
     def test_safe_attrs(self):
         assert Box()._safe_attr("BAD!KEY!1") == "BAD_KEY_1"
         assert Box(camel_killer_box=True)._safe_attr("BAD!KEY!2") == "bad_key_2"