diff --git a/thread_pthread.c b/thread_pthread.c
index 730ecb5416..83fd37d0ea 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -3166,20 +3166,26 @@ rb_thread_create_timer_thread(void)
         timer_thread_setup_mn();
     }
 
-    pthread_create(&timer_th.pthread_id, NULL, timer_thread_func, GET_VM());
+    if (pthread_create(&timer_th.pthread_id, NULL, timer_thread_func, GET_VM()) != 0) {
+        system_working = 0;
+        // NOTE: safe to call into VM here even if we're in the middle of a call to `rb_fork_ruby()`
+        rb_warn("Couldn't create timer thread, error: %s", strerror(errno));
+    }
 }
 
 static int
 native_stop_timer_thread(void)
 {
-    RUBY_ATOMIC_SET(system_working, 0);
+    if (RUBY_ATOMIC_LOAD(system_working)) {
+        RUBY_ATOMIC_SET(system_working, 0);
 
-    RUBY_DEBUG_LOG("wakeup send %d", timer_th.comm_fds[1]);
-    timer_thread_wakeup_force();
-    RUBY_DEBUG_LOG("wakeup sent");
-    pthread_join(timer_th.pthread_id, NULL);
+        RUBY_DEBUG_LOG("wakeup send %d", timer_th.comm_fds[1]);
+        timer_thread_wakeup_force();
+        RUBY_DEBUG_LOG("wakeup sent");
+        pthread_join(timer_th.pthread_id, NULL);
 
-    if (TT_DEBUG) fprintf(stderr, "stop timer thread\n");
+        if (TT_DEBUG) fprintf(stderr, "stop timer thread\n");
+    }
 
     return 1;
 }
diff --git a/thread_win32.c b/thread_win32.c
index 576f617e8d..0944e22fba 100644
--- a/thread_win32.c
+++ b/thread_win32.c
@@ -797,19 +797,27 @@ rb_thread_create_timer_thread(void)
         }
         timer_thread.id = w32_create_thread(1024 + (USE_RUBY_DEBUG_LOG ? BUFSIZ : 0),
                                             timer_thread_func, 0);
-        w32_resume_thread(timer_thread.id);
+        if (timer_thread.id == 0) {
+            system_working = 0;
+            rb_warn("Couldn't create timer thread, error:%s", strerror(thread_errno));
+        }
+        else {
+            w32_resume_thread(timer_thread.id);
+        }
     }
 }
 
 static int
 native_stop_timer_thread(void)
 {
-    RUBY_ATOMIC_SET(system_working, 0);
+    if (RUBY_ATOMIC_LOAD(system_working)) {
+        RUBY_ATOMIC_SET(system_working, 0);
 
-    SetEvent(timer_thread.lock);
-    native_thread_join(timer_thread.id);
-    CloseHandle(timer_thread.lock);
-    timer_thread.lock = 0;
+        SetEvent(timer_thread.lock);
+        native_thread_join(timer_thread.id);
+        CloseHandle(timer_thread.lock);
+        timer_thread.lock = 0;
+    }
 
     return 1;
 }