diff --git a/bin/chcp.c b/bin/chcp.c
index 07e9f2b..79aea01 100644
--- a/bin/chcp.c
+++ b/bin/chcp.c
@@ -86,8 +86,6 @@ int main(int argc, char *argv[])
 #endif	/* _GNU_SOURCE */
 	sigset_t sigset, oldset;
 
-	opterr = 0;
-
 	last = strrchr(argv[0], '/');
 	progname = last ? last + 1 : argv[0];
 
@@ -107,7 +105,7 @@ int main(int argc, char *argv[])
 			       PACKAGE_VERSION);
 			exit(EXIT_SUCCESS);
 		default:
-			errx(EXIT_FAILURE, "invalid option -- %c", optopt);
+			exit(EXIT_FAILURE);
 		}
 	}
 
diff --git a/bin/dumpseg.c b/bin/dumpseg.c
index 7fbbc12..a2a4f7d 100644
--- a/bin/dumpseg.c
+++ b/bin/dumpseg.c
@@ -264,8 +264,6 @@ int main(int argc, char *argv[])
 	int option_index;
 #endif	/* _GNU_SOURCE */
 
-	opterr = 0;
-
 	last = strrchr(argv[0], '/');
 	progname = last ? last + 1 : argv[0];
 
@@ -285,7 +283,7 @@ int main(int argc, char *argv[])
 			       PACKAGE_VERSION);
 			exit(EXIT_SUCCESS);
 		default:
-			errx(EXIT_FAILURE, "invalid option -- %c", optopt);
+			exit(EXIT_FAILURE);
 		}
 	}
 
diff --git a/bin/lscp.c b/bin/lscp.c
index c20ef25..03a842d 100644
--- a/bin/lscp.c
+++ b/bin/lscp.c
@@ -418,7 +418,6 @@ int main(int argc, char *argv[])
 
 	mode = NILFS_CHECKPOINT;
 	rvs = 0;
-	opterr = 0;	/* prevent error message */
 	progname = strrchr(argv[0], '/');
 	if (progname == NULL)
 		progname = argv[0];
@@ -463,7 +462,7 @@ int main(int argc, char *argv[])
 			       PACKAGE_VERSION);
 			exit(EXIT_SUCCESS);
 		default:
-			errx(EXIT_FAILURE, "invalid option -- %c", optopt);
+			exit(EXIT_FAILURE);
 		}
 	}
 
diff --git a/bin/lssu.c b/bin/lssu.c
index c4534ce..4cdf477 100644
--- a/bin/lssu.c
+++ b/bin/lssu.c
@@ -298,7 +298,6 @@ int main(int argc, char *argv[])
 	int option_index;
 #endif	/* _GNU_SOURCE */
 
-	opterr = 0;
 	progname = strrchr(argv[0], '/');
 	if (progname == NULL)
 		progname = argv[0];
@@ -345,7 +344,7 @@ int main(int argc, char *argv[])
 			       PACKAGE_VERSION);
 			exit(EXIT_SUCCESS);
 		default:
-			errx(EXIT_FAILURE, "invalid option -- %c", optopt);
+			exit(EXIT_FAILURE);
 		}
 	}
 
diff --git a/bin/mkcp.c b/bin/mkcp.c
index 4f201b3..677d599 100644
--- a/bin/mkcp.c
+++ b/bin/mkcp.c
@@ -81,7 +81,6 @@ int main(int argc, char *argv[])
 
 	ss = 0;
 	print = 0;
-	opterr = 0;
 	last = strrchr(argv[0], '/');
 	progname = last ? last + 1 : argv[0];
 
@@ -107,7 +106,7 @@ int main(int argc, char *argv[])
 			       PACKAGE_VERSION);
 			exit(EXIT_SUCCESS);
 		default:
-			errx(EXIT_FAILURE, "invalid option -- %c", optopt);
+			exit(EXIT_FAILURE);
 		}
 	}
 
diff --git a/bin/rmcp.c b/bin/rmcp.c
index d852a2a..9d3afd8 100644
--- a/bin/rmcp.c
+++ b/bin/rmcp.c
@@ -147,7 +147,6 @@ int main(int argc, char *argv[])
 	int option_index;
 #endif	/* _GNU_SOURCE */
 
-	opterr = 0;
 	last = strrchr(argv[0], '/');
 	progname = last ? last + 1 : argv[0];
 
@@ -175,7 +174,7 @@ int main(int argc, char *argv[])
 			       PACKAGE_VERSION);
 			exit(EXIT_SUCCESS);
 		default:
-			errx(EXIT_FAILURE, "invalid option -- %c", optopt);
+			exit(EXIT_FAILURE);
 		}
 	}