diff --git a/arg.h b/arg.h
index f1fbdf3..c997fd0 100644
--- a/arg.h
+++ b/arg.h
@@ -46,7 +46,7 @@ extern char *argv0;
 
 #define ARGC()		argc_
 
-#define ARGNUMF(base)	(brk_ = 1, estrtonum(argv[0], 0, INT_MAX))
+#define ARGNUMF()	(brk_ = 1, estrtonum(argv[0], 0, INT_MAX))
 
 #define EARGF(x)	((argv[0][1] == '\0' && argv[1] == NULL)?\
 				((x), abort(), (char *)0) :\
diff --git a/fold.c b/fold.c
index 06f09ca..03286de 100644
--- a/fold.c
+++ b/fold.c
@@ -87,7 +87,7 @@ main(int argc, char *argv[])
 		width = estrtonum(EARGF(usage()), 1, LLONG_MAX);
 		break;
 	ARGNUM:
-		width = ARGNUMF(10);
+		width = ARGNUMF();
 		break;
 	default:
 		usage();
diff --git a/head.c b/head.c
index 1a83a7e..31845d3 100644
--- a/head.c
+++ b/head.c
@@ -44,7 +44,7 @@ main(int argc, char *argv[])
 		n = estrtonum(EARGF(usage()), 0, LONG_MAX);
 		break;
 	ARGNUM:
-		n = ARGNUMF(0);
+		n = ARGNUMF();
 		break;
 	default:
 		usage();
diff --git a/tail.c b/tail.c
index 494b6af..a678a93 100644
--- a/tail.c
+++ b/tail.c
@@ -35,7 +35,7 @@ main(int argc, char *argv[])
 			tail = dropinit;
 		break;
 	ARGNUM:
-		n = ARGNUMF(0);
+		n = ARGNUMF();
 		break;
 	default:
 		usage();