diff --git a/lib/args.c b/lib/args.c
index 2c17951..c9ade1e 100644
--- a/lib/args.c
+++ b/lib/args.c
@@ -108,7 +108,7 @@
 			temp->arg = gof.arg;
 			temp->next = *list;
 			*list = temp;
-		} else if (type == '#') *(gof.this->arg) = atol((char *)gof.arg);
+		} else if (type == '#') *(gof.this->arg) = atolx((char *)gof.arg);
 		else if (type == '@') {
 		}
 
diff --git a/lib/lib.c b/lib/lib.c
index f1d1ce1..6c8abb0 100644
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -402,6 +402,18 @@
 	return itoa_buf;
 }
 
+// atol() with the kilo/mega/giga/tera/peta/exa extensions.
+// (zetta and yotta don't fit in 64 bits.)
+long atolx(char *c)
+{
+	char *suffixes="kmgtpe", *end;
+	long val = strtol(c, &c, 0);
+
+	end = strchr(suffixes, tolower(*c));
+	if (end) val *= 1024<<((end-suffixes)*10);
+	return val;
+}
+
 // Return how long the file at fd is, if there's any way to determine it.
 off_t fdlength(int fd)
 {
diff --git a/lib/lib.h b/lib/lib.h
index 07cc9cd..e2d055b 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -65,6 +65,7 @@
 void itoa_to_buf(int n, char *buf, unsigned buflen);
 char *utoa(unsigned n);
 char *itoa(int n);
+long atolx(char *c);
 off_t fdlength(int fd);
 struct dirtree *read_dirtree_node(char *path);
 struct dirtree *read_dirtree(char *path, struct dirtree *parent);