diff --git a/src/proc.h b/src/proc.h
index 388cda972..d1de80641 100644
--- a/src/proc.h
+++ b/src/proc.h
@@ -294,8 +294,8 @@ extern bool is_login;
 /// nesting level.
 extern int is_event;
 
-// List of jobs.
-using job_list_t = std::deque<shared_ptr<job_t>>;
+// List of jobs. We sometimes mutate this while iterating - hence it must be a list, not a vector
+typedef std::deque<shared_ptr<job_t>> job_list_t;
 
 bool job_list_is_empty(void);