diff --git a/selfdrive/manager/process.py b/selfdrive/manager/process.py
index b7af893c05..8edd102d57 100644
--- a/selfdrive/manager/process.py
+++ b/selfdrive/manager/process.py
@@ -107,6 +107,10 @@ class ManagerProcess(ABC):
     return ret
 
   def signal(self, sig):
+    if self.proc is None:
+      return
+
+    # Don't signal if already exited
     if self.proc.exitcode is not None and self.proc.pid is not None:
       return