diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6c6e10b..75313a9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+- 🐛 Raise SystemExit when port-forwarding is enabled and local port is not available. PR [#48](https://github.com/NCAR/jupyter-forward/pull/48) by [@andersy005](https://github.com/andersy005)
+
 ## v2020.10.27
 
 - ⚡ Use try block to exit gracefully. PR [#45](https://github.com/NCAR/jupyter-forward/pull/45) by [@andersy005](https://github.com/andersy005)
diff --git a/jupyter_forward/core.py b/jupyter_forward/core.py
index dc02ef2..41f987f 100644
--- a/jupyter_forward/core.py
+++ b/jupyter_forward/core.py
@@ -35,7 +35,7 @@ class RemoteRunner:
     shell: str = '/usr/bin/env bash'
 
     def __post_init__(self):
-        if not is_port_available(self.port):
+        if self.port_forwarding and not is_port_available(self.port):
             raise SystemExit(
                 (
                     f'''Specified port={self.port} is already in use on your local machine. Try a different port'''