diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
index 6341767..8e713be 100644
--- a/tools/libxl/xl_cmdimpl.c
+++ b/tools/libxl/xl_cmdimpl.c
@@ -2955,7 +2955,7 @@ int main_dump_core(int argc, char **argv)
             help("dump-core");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -3462,7 +3462,7 @@ int main_vcpulist(int argc, char **argv)
             help("vcpu-list");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -3553,7 +3553,7 @@ int main_vcpupin(int argc, char **argv)
             help("vcpu-pin");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -3598,7 +3598,7 @@ int main_vcpuset(int argc, char **argv)
         help("vcpu-set");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -3762,7 +3762,7 @@ int main_info(int argc, char **argv)
             numa = 1;
             break;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -3834,7 +3834,7 @@ int main_sched_credit(int argc, char **argv)
             help("sched-credit");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -3893,7 +3893,7 @@ int main_domid(int argc, char **argv)
             help("domid");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -3927,7 +3927,7 @@ int main_domname(int argc, char **argv)
             help("domname");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -3968,7 +3968,7 @@ int main_rename(int argc, char **argv)
             help("rename");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4005,7 +4005,7 @@ int main_trigger(int argc, char **argv)
             help("trigger");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4046,7 +4046,7 @@ int main_sysrq(int argc, char **argv)
             help("sysrq");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4146,7 +4146,7 @@ int main_top(int argc, char **argv)
             help("top");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4169,7 +4169,7 @@ int main_networkattach(int argc, char **argv)
             help("network-attach");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4250,7 +4250,7 @@ int main_networklist(int argc, char **argv)
                 help("network-list");
                 return 0;
             default:
-                fprintf(stderr, "option `%c' not supported.\n", opt);
+                fprintf(stderr, "option `%c' not supported.\n", optopt);
                 break;
         }
     }
@@ -4299,7 +4299,7 @@ int main_networkdetach(int argc, char **argv)
             help("network-detach");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4345,7 +4345,7 @@ int main_blockattach(int argc, char **argv)
             help("block-attach");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4418,7 +4418,7 @@ int main_blocklist(int argc, char **argv)
             help("block-list");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4464,7 +4464,7 @@ int main_blockdetach(int argc, char **argv)
             help("block-detach");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4503,7 +4503,7 @@ int main_network2attach(int argc, char **argv)
             help("network2-attach");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4596,7 +4596,7 @@ int main_network2list(int argc, char **argv)
             help("network2-list");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4640,7 +4640,7 @@ int main_network2detach(int argc, char **argv)
             help("network2-detach");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4839,7 +4839,7 @@ int main_uptime(int argc, char **argv)
             help("uptime");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4874,7 +4874,7 @@ int main_tmem_list(int argc, char **argv)
             help("tmem-list");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4915,7 +4915,7 @@ int main_tmem_freeze(int argc, char **argv)
             help("tmem-freeze");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4951,7 +4951,7 @@ int main_tmem_destroy(int argc, char **argv)
             help("tmem-destroy");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -4987,7 +4987,7 @@ int main_tmem_thaw(int argc, char **argv)
             help("tmem-thaw");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5037,7 +5037,7 @@ int main_tmem_set(int argc, char **argv)
             help("tmem-set");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5095,7 +5095,7 @@ int main_tmem_shared_auth(int argc, char **argv)
             help("tmem-shared-auth");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5140,7 +5140,7 @@ int main_tmem_freeable(int argc, char **argv)
             help("tmem-freeable");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5468,7 +5468,7 @@ int main_cpupooldestroy(int argc, char **argv)
             help("cpupool-destroy");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5502,7 +5502,7 @@ int main_cpupoolrename(int argc, char **argv)
             help("cpupool-rename");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5545,7 +5545,7 @@ int main_cpupoolcpuadd(int argc, char **argv)
             help("cpupool-cpu-add");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5608,7 +5608,7 @@ int main_cpupoolcpuremove(int argc, char **argv)
             help("cpupool-cpu-remove");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5670,7 +5670,7 @@ int main_cpupoolmigrate(int argc, char **argv)
             help("cpupool-migrate");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }
@@ -5727,7 +5727,7 @@ int main_cpupoolnumasplit(int argc, char **argv)
             help("cpupool-numa-split");
             return 0;
         default:
-            fprintf(stderr, "option `%c' not supported.\n", opt);
+            fprintf(stderr, "option `%c' not supported.\n", optopt);
             break;
         }
     }