diff --git a/gc.c b/gc.c
index b3edb99..68665fe 100644
--- a/gc.c
+++ b/gc.c
@@ -1694,7 +1694,7 @@ void fprint_gc_stats(FILE *f)
         ns2sec(gc_stats.gen[1].max_ns));
 
     fprintf(f, "GC: The Gen-1 soft-limit peaked at %d bytes out of %d allocated.\n",
-        gc_stats.gen1_high_water, gc_gen1_max_size);
+        (int)gc_stats.gen1_high_water, (int)gc_gen1_max_size);
   }
   else
   {