diff --git a/ports/espressif/supervisor/port.c b/ports/espressif/supervisor/port.c
index 0169f5ce16..78c3508458 100644
--- a/ports/espressif/supervisor/port.c
+++ b/ports/espressif/supervisor/port.c
@@ -235,6 +235,7 @@ safe_mode_t port_init(void) {
         heap_size = HEAP_SIZE / sizeof(uint32_t);
     }
     if (heap == NULL) {
+        heap_size = 0;
         return NO_HEAP;
     }