diff --git a/src/gc.c b/src/gc.c
index c67454f5f..bf544fc12 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -1277,6 +1277,7 @@ mrb_full_gc(mrb_state *mrb)
 {
   mrb_gc *gc = &mrb->gc;
 
+  if (!mrb->c) return;
   if (gc->disabled || gc->iterating) return;
 
   GC_INVOKE_TIME_REPORT("mrb_full_gc()");