diff --git a/Cargo.lock b/Cargo.lock
index 18e0369..006e91b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -271,6 +271,7 @@ dependencies = [
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyperjson 0.2.2",
  "pyo3 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
  "structopt 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
diff --git a/profiling/Cargo.toml b/profiling/Cargo.toml
index 276a12f..bdefd23 100644
--- a/profiling/Cargo.toml
+++ b/profiling/Cargo.toml
@@ -2,12 +2,14 @@
 name = "profiling"
 version = "0.1.0"
 authors = ["Matthias Endler <matthias-endler@gmx.net>"]
+edition = "2018"
 
 [dependencies]
 # Disabling the default features makes pyo3 choose binary linking
 hyperjson = { path = "..", default-features = false }
 structopt = "0.3.2"
 clap = "2.33.0"
+serde_json = "1.0.40"
 
 [dependencies.pyo3]
 version = "0.8.0"
diff --git a/profiling/src/main.rs b/profiling/src/main.rs
index f94f1b8..b4fb939 100644
--- a/profiling/src/main.rs
+++ b/profiling/src/main.rs
@@ -14,16 +14,11 @@
 //! callgrind_annotate --auto=yes callgrind.out.35583 >out.rs
 //! qcachegrind callgrind.out.35583
 //! ```
-extern crate structopt;
-#[macro_use]
-extern crate clap;
-
-extern crate hyperjson;
-extern crate pyo3;
 
 mod profiles;
 
 use structopt::StructOpt;
+use clap::arg_enum;
 
 arg_enum! {
     #[derive(Debug)]
diff --git a/src/lib.rs b/src/lib.rs
index 5792271..0467715 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,22 +1,16 @@
 #![feature(test)]
 
-#[macro_use]
-extern crate failure;
-#[macro_use]
-extern crate pyo3;
-extern crate serde;
-extern crate serde_derive;
-extern crate serde_json;
-extern crate test;
-
 use std::collections::BTreeMap;
 use std::fmt;
 use std::marker::PhantomData;
+use failure::Fail;
 
 use pyo3::prelude::*;
 use pyo3::exceptions::TypeError as PyTypeError;
 use pyo3::exceptions::ValueError as PyValueError;
 use pyo3::types::{PyDict, PyFloat, PyList, PyAny, PyTuple};
+use pyo3::{import_exception, wrap_pyfunction};
+
 use serde::de::{self, DeserializeSeed, Deserializer, MapAccess, SeqAccess, Visitor};
 use serde::ser::{self, Serialize, SerializeMap, SerializeSeq, Serializer};