diff --git a/rts/Schedule.c b/rts/Schedule.c
index 061de639b28f2ea1e1c0b7ff87f5e09d0309e9f2..204f356554e50ae97c903571f4315521728885ae 100644
--- a/rts/Schedule.c
+++ b/rts/Schedule.c
@@ -2157,7 +2157,6 @@ forkProcess(HsStablePtr *entry
         // On Unix, all timers are reset in the child, so we need to start
         // the timer again.
         initTimer();
-        startTimer();
 
         // TODO: need to trace various other things in the child
         // like startup event, capabilities, process info etc
@@ -2167,6 +2166,10 @@ forkProcess(HsStablePtr *entry
         ioManagerStartCap(&cap);
 #endif
 
+        // start timer after the IOManager is initialized
+        // (the idle GC may wake up the IOManager)
+        startTimer();
+
         // Install toplevel exception handlers, so interruption
         // signal will be sent to the main thread.
         // See #12903
diff --git a/rts/posix/itimer/Pthread.c b/rts/posix/itimer/Pthread.c
index 73b1eba5def6401d34d0328e2138a0a8d6dd4a0e..738e5ec469cc3a3ebd09c3c7c0caf3ffadfecac5 100644
--- a/rts/posix/itimer/Pthread.c
+++ b/rts/posix/itimer/Pthread.c
@@ -168,7 +168,7 @@ void
 initTicker (Time interval, TickProc handle_tick)
 {
     itimer_interval = interval;
-    stopped = false;
+    stopped = true;
     exited = false;
 #if defined(HAVE_SIGNAL_H)
     sigset_t mask, omask;