diff --git a/src/flog.h b/src/flog.h
index 111f0476e..cba1d4aac 100644
--- a/src/flog.h
+++ b/src/flog.h
@@ -74,6 +74,7 @@ class category_list_t {
                                   L"Reaping internal (non-forked) processes"};
 
     category_t proc_reap_external{L"proc-reap-external", L"Reaping external (forked) processes"};
+    category_t proc_pgroup{L"proc-pgroup", L"Process groups"};
 
     category_t env_locale{L"env-locale", L"Changes to locale variables"};
 
diff --git a/src/postfork.cpp b/src/postfork.cpp
index c3e0a77b2..4dfad691f 100644
--- a/src/postfork.cpp
+++ b/src/postfork.cpp
@@ -124,7 +124,7 @@ bool set_child_group(job_t *j, pid_t child_pid) {
                 // ever leads to a terminal hang due if both this setpgid call AND posix_spawn's
                 // internal setpgid calls failed), write to the debug log so a future developer
                 // doesn't go crazy trying to track this down.
-                debug(2, "Error %d while calling setpgid for child %d (probably harmless)", errno,
+                FLOGF(proc_pgroup, "Error %d while calling setpgid for child %d (probably harmless)", errno,
                       child_pid);
             }
         }
diff --git a/src/proc.cpp b/src/proc.cpp
index 03ce28c47..324ea3fa4 100644
--- a/src/proc.cpp
+++ b/src/proc.cpp
@@ -798,7 +798,7 @@ pid_t terminal_acquire_before_builtin(int job_pgid) {
 static bool terminal_return_from_job(job_t *j, int restore_attrs) {
     errno = 0;
     if (j->pgid == 0) {
-        debug(2, "terminal_return_from_job() returning early due to no process group");
+        FLOG(proc_pgroup, "terminal_return_from_job() returning early due to no process group");
         return true;
     }
 
@@ -868,7 +868,7 @@ void job_t::continue_job(parser_t &parser, bool reclaim_foreground_pgrp, bool se
             // signal individually. job_t::signal() does the same, but uses the shell's own pgroup
             // to make that distinction.
             if (!signal(SIGCONT)) {
-                debug(2, "Failed to send SIGCONT to any processes in pgroup %d!", pgid);
+                FLOGF(proc_pgroup, "Failed to send SIGCONT to any processes in pgroup %d!", pgid);
                 // This returns without bubbling up the error. Presumably that is OK.
                 return;
             }