diff --git a/src/cpu/cpu.c b/src/cpu/cpu.c
index 694ee1155..3380e7ce4 100644
--- a/src/cpu/cpu.c
+++ b/src/cpu/cpu.c
@@ -1520,7 +1520,7 @@ cpu_set(void)
             break;
 
         default:
-            fatal("cpu_set : unknown CPU type %i\n", cpu_s->cpu_type);
+            fatal("cpu_set : unknown CPU type %llu\n", cpu_s->cpu_type);
     }
 
     switch (fpu_type) {