diff --git a/docs/changelog.md b/docs/changelog.md
index 55d0d42..625ee7a 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## `0.0.4`
+
+Released `2024-10-24`
+
+### Fixed
+
+- [#79](https://github.com/JoshKarpel/synthesize/pull/79)
+  Fix a crash that could happen when a process exits while we are trying to terminate it.
+
 ## `0.0.3`
 
 Released `2024-07-07`
diff --git a/synthesize/execution.py b/synthesize/execution.py
index 3d34768..e990585 100644
--- a/synthesize/execution.py
+++ b/synthesize/execution.py
@@ -110,7 +110,11 @@ def _send_signal(self, signal: int) -> None:
         if self.has_exited:
             return None
 
-        os.killpg(os.getpgid(self.process.pid), signal)
+        try:
+            os.killpg(os.getpgid(self.process.pid), signal)
+        except ProcessLookupError:
+            # process exited before we could send the signal
+            pass
 
     def terminate(self) -> None:
         self._send_signal(SIGTERM)