diff --git a/Cargo.lock b/Cargo.lock
index e9aee75..f4ba229 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -189,10 +189,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "proc-macro-error"
-version = "0.4.12"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "proc-macro-error-attr 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro-error-attr 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -201,7 +201,7 @@ dependencies = [
 
 [[package]]
 name = "proc-macro-error-attr"
-version = "0.4.12"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "proc-macro2 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -323,21 +323,21 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "structopt"
-version = "0.3.12"
+version = "0.3.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "structopt-derive 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "structopt-derive 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "structopt-derive"
-version = "0.4.5"
+version = "0.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "heck 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "proc-macro-error 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proc-macro-error 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro2 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "syn 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -439,7 +439,7 @@ dependencies = [
  "dirs 2.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "dunce 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.106 (registry+https://github.com/rust-lang/crates.io-index)",
- "structopt 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)",
+ "structopt 0.3.13 (registry+https://github.com/rust-lang/crates.io-index)",
  "uuid 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -470,8 +470,8 @@ dependencies = [
 "checksum libc 0.2.68 (registry+https://github.com/rust-lang/crates.io-index)" = "dea0c0405123bba743ee3f91f49b1c7cfb684eef0da0a50110f758ccf24cdff0"
 "checksum memchr 2.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3728d817d99e5ac407411fa471ff9800a778d88a24685968b36824eaf4bee400"
 "checksum ppv-lite86 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "74490b50b9fbe561ac330df47c08f3f33073d2d00c150f719147d7c54522fa1b"
-"checksum proc-macro-error 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "18f33027081eba0a6d8aba6d1b1c3a3be58cbb12106341c2d5759fcd9b5277e7"
-"checksum proc-macro-error-attr 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)" = "8a5b4b77fdb63c1eca72173d68d24501c54ab1269409f6b672c85deb18af69de"
+"checksum proc-macro-error 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "98e9e4b82e0ef281812565ea4751049f1bdcdfccda7d3f459f2e138a40c08678"
+"checksum proc-macro-error-attr 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4f5444ead4e9935abd7f27dc51f7e852a0569ac888096d5ec2499470794e2e53"
 "checksum proc-macro2 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)" = "df246d292ff63439fea9bc8c0a270bed0e390d5ebd4db4ba15aba81111b5abe3"
 "checksum quote 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2bdc6c187c65bca4260c9011c9e3132efe4909da44726bad24cf7572ae338d7f"
 "checksum rand 0.7.3 (registry+https://github.com/rust-lang/crates.io-index)" = "6a6b1679d49b24bbfe0c803429aa1874472f50d9b363131f0e89fc356b544d03"
@@ -485,8 +485,8 @@ dependencies = [
 "checksum serde 1.0.106 (registry+https://github.com/rust-lang/crates.io-index)" = "36df6ac6412072f67cf767ebbde4133a5b2e88e76dc6187fa7104cd16f783399"
 "checksum serde_derive 1.0.106 (registry+https://github.com/rust-lang/crates.io-index)" = "9e549e3abf4fb8621bd1609f11dfc9f5e50320802273b12f3811a67e6716ea6c"
 "checksum strsim 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "8ea5119cdb4c55b55d432abb513a0429384878c15dde60cc77b1c99de1a95a6a"
-"checksum structopt 0.3.12 (registry+https://github.com/rust-lang/crates.io-index)" = "c8faa2719539bbe9d77869bfb15d4ee769f99525e707931452c97b693b3f159d"
-"checksum structopt-derive 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)" = "3f88b8e18c69496aad6f9ddf4630dd7d585bcaf765786cb415b9aec2fe5a0430"
+"checksum structopt 0.3.13 (registry+https://github.com/rust-lang/crates.io-index)" = "ff6da2e8d107dfd7b74df5ef4d205c6aebee0706c647f6bc6a2d5789905c00fb"
+"checksum structopt-derive 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)" = "a489c87c08fbaf12e386665109dd13470dcc9c4583ea3e10dd2b4523e5ebd9ac"
 "checksum syn 1.0.17 (registry+https://github.com/rust-lang/crates.io-index)" = "0df0eb663f387145cab623dea85b09c2c5b4b0aef44e945d928e682fce71bb03"
 "checksum syn-mid 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "7be3539f6c128a931cf19dcee741c1af532c7fd387baa739c03dd2e96479338a"
 "checksum textwrap 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d326610f408c7a4eb6f51c37c330e496b08506c9457c9d34287ecc38809fb060"
diff --git a/src/dir.rs b/src/dir.rs
index efb4378..b07cd53 100644
--- a/src/dir.rs
+++ b/src/dir.rs
@@ -5,7 +5,7 @@ use std::path::{Path, PathBuf};
 pub use f64 as Rank;
 pub use i64 as Epoch; // use a signed integer so subtraction can be performed on it
 
-#[derive(Debug, Default, Deserialize, Serialize)]
+#[derive(Debug, Deserialize, Serialize)]
 pub struct Dir {
     pub path: PathBuf,
     pub rank: Rank,