diff --git a/CHANGELOG.md b/CHANGELOG.md
index 99a72b7..db38f82 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
 - `WinMM` engine
 ### Changed
+- `run` function in NavaThread
+- `stop` function in NavaThread
 - `README.md` updated
 - Test system modified
 - `Python 3.6` support dropped
diff --git a/nava/thread.py b/nava/thread.py
index 8971c00..a5a2d57 100644
--- a/nava/thread.py
+++ b/nava/thread.py
@@ -38,7 +38,7 @@ def run(self):
         try:
             if self._target is not None:
                 if self._engine == Engine.WINSOUND or self._engine == Engine.WINMM:
-                    _ = self._target(*self._args, **self._kwargs)
+                    self._target(*self._args, **self._kwargs)
                 else:
                     while True:
                         self._play_process = self._target(*self._args, **self._kwargs)
@@ -62,16 +62,29 @@ def stop(self):
         elif self._engine == Engine.WINMM:
             self._force_stop = True
             # The alias is scoped to the MCI (Media Control Interface) context of the thread that created it.
-            # So the main thread can’t “see” the alias created in the worker thread.
+            # So the main thread can't "see" the alias created in the worker thread.
         else:
-            if self._play_process is not None:
+            if self._play_process:
+                # Best-effort: close all standard streams
                 try:
                     self._play_process.stdout.close()
                     self._play_process.stdin.close()
                     self._play_process.stderr.close()
-                    self._play_process.kill()
-                    self._play_process.terminate()
-                except ProcessLookupError:
+                except Exception:  # nosec B110 - Best effort cleanup, ignore all errors
+                    # Streams may be None, already closed, or OS-specific issues
                     pass
+
+                # Try graceful termination
+                try:
+                    self._play_process.terminate()
+                    self._play_process.wait(timeout=1)
+                except Exception:
+                    # Fallback to force kill - catch any process-related errors
+                    try:
+                        self._play_process.kill()
+                        self._play_process.wait()
+                    except Exception:  # nosec B110 - Best effort cleanup, ignore all errors
+                        # Process already terminated or any other issues
+                        pass
                 finally:
-                    self._play_process.wait()
+                    self._play_process = None