diff --git a/ports/esp32s2/supervisor/port.c b/ports/esp32s2/supervisor/port.c
index 47d0c7f463..876ad739d6 100644
--- a/ports/esp32s2/supervisor/port.c
+++ b/ports/esp32s2/supervisor/port.c
@@ -191,14 +191,14 @@ uint32_t port_get_saved_word(void) {
 }
 
 uint64_t port_get_raw_ticks(uint8_t* subticks) {
-    struct timeval tv_now;
-    gettimeofday(&tv_now, NULL);
-    // convert usec back to ticks
-    uint64_t all_subticks = (uint64_t)(tv_now.tv_usec * 2) / 71;
+    // Convert microseconds to subticks of 1/32768 seconds
+    // 32768/1000000 = 64/15625 in lowest terms
+    // this arithmetic overflows after 570 years
+    int64_t all_subticks = esp_timer_get_time() * 512 / 15625;
     if (subticks != NULL) {
         *subticks = all_subticks % 32;
     }
-    return (uint64_t)tv_now.tv_sec * 1024L + all_subticks / 32;
+    return all_subticks / 32;
 }
 
 // Enable 1/1024 second tick.