diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index ab811567..5d67424a 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -10,6 +10,7 @@ description = """
 An RDF and SPARQL library in Rust
 """
 build = "build.rs"
+edition = "2018"
 
 [badges]
 travis-ci = { repository = "Tpt/rudf" }
diff --git a/lib/src/rio/ntriples/ntriples_grammar.rustpeg b/lib/src/rio/ntriples/ntriples_grammar.rustpeg
index ec081bde..1f3aa105 100644
--- a/lib/src/rio/ntriples/ntriples_grammar.rustpeg
+++ b/lib/src/rio/ntriples/ntriples_grammar.rustpeg
@@ -2,9 +2,9 @@
 
 use std::char;
 use std::str::FromStr;
-use model::*;
+use crate::model::*;
 use std::collections::BTreeMap;
-use rio::utils::unescape_unicode_codepoints;
+use crate::rio::utils::unescape_unicode_codepoints;
 
 #![arguments(bnodes_map: &mut BTreeMap<String, BlankNode>)]
 
diff --git a/lib/src/rio/turtle/turtle_grammar.rustpeg b/lib/src/rio/turtle/turtle_grammar.rustpeg
index d2385847..1025e0c2 100644
--- a/lib/src/rio/turtle/turtle_grammar.rustpeg
+++ b/lib/src/rio/turtle/turtle_grammar.rustpeg
@@ -1,10 +1,10 @@
 //See https://www.w3.org/TR/turtle/#sec-grammar
 
 use std::char;
-use model::vocab::rdf;
-use model::vocab::xsd;
+use crate::model::vocab::rdf;
+use crate::model::vocab::xsd;
 use std::str::FromStr;
-use rio::utils::unescape_unicode_codepoints;
+use crate::rio::utils::unescape_unicode_codepoints;
 
 #![arguments(state: &mut ParserState, buffer: &mut Vec<Triple>)]
 
diff --git a/lib/src/sparql/sparql_grammar.rustpeg b/lib/src/sparql/sparql_grammar.rustpeg
index 0d194a85..a1d16858 100644
--- a/lib/src/sparql/sparql_grammar.rustpeg
+++ b/lib/src/sparql/sparql_grammar.rustpeg
@@ -1,8 +1,8 @@
 //See https://www.w3.org/TR/turtle/#sec-grammar
 
 use std::char;
-use model::vocab::rdf;
-use model::vocab::xsd;
+use crate::model::vocab::rdf;
+use crate::model::vocab::xsd;
 use std::str::FromStr;
 
 #![arguments(state: &mut ParserState)]
diff --git a/lib/src/store/memory.rs b/lib/src/store/memory.rs
index c390c295..2dbfaf6e 100644
--- a/lib/src/store/memory.rs
+++ b/lib/src/store/memory.rs
@@ -419,9 +419,9 @@ impl EncodedQuadsStore for MemoryStore {
         if let Some(graph) = graph_indexes.get_mut(&quad.graph_name) {
             {
                 let mut empty_pos = false;
-                if let Some(mut pos) = graph.spo.get_mut(&quad.subject) {
+                if let Some(pos) = graph.spo.get_mut(&quad.subject) {
                     let mut empty_os = false;
-                    if let Some(mut os) = pos.get_mut(&quad.predicate) {
+                    if let Some(os) = pos.get_mut(&quad.predicate) {
                         os.remove(&quad.object);
                         empty_os = os.is_empty();
                     }
@@ -437,9 +437,9 @@ impl EncodedQuadsStore for MemoryStore {
 
             {
                 let mut empty_oss = false;
-                if let Some(mut oss) = graph.pos.get_mut(&quad.predicate) {
+                if let Some(oss) = graph.pos.get_mut(&quad.predicate) {
                     let mut empty_ss = false;
-                    if let Some(mut ss) = oss.get_mut(&quad.object) {
+                    if let Some(ss) = oss.get_mut(&quad.object) {
                         ss.remove(&quad.subject);
                         empty_ss = ss.is_empty();
                     }
@@ -455,9 +455,9 @@ impl EncodedQuadsStore for MemoryStore {
 
             {
                 let mut empty_sps = false;
-                if let Some(mut sps) = graph.osp.get_mut(&quad.object) {
+                if let Some(sps) = graph.osp.get_mut(&quad.object) {
                     let mut empty_ps = false;
-                    if let Some(mut ps) = sps.get_mut(&quad.subject) {
+                    if let Some(ps) = sps.get_mut(&quad.subject) {
                         ps.remove(&quad.predicate);
                         empty_ps = ps.is_empty();
                     }
diff --git a/python/Cargo.toml b/python/Cargo.toml
index 524abd07..f4a93438 100644
--- a/python/Cargo.toml
+++ b/python/Cargo.toml
@@ -9,6 +9,7 @@ repository = "https://github.com/Tpt/rudf"
 description = """
 Python bindings of the Rudf library
 """
+edition = "2018"
 
 [lib]
 name = "rudf"
diff --git a/server/Cargo.toml b/server/Cargo.toml
index b663c435..c61dc9c9 100644
--- a/server/Cargo.toml
+++ b/server/Cargo.toml
@@ -8,6 +8,7 @@ repository = "https://github.com/Tpt/rudf"
 description = """
 Rudf based SPARQL server
 """
+edition = "2018"
 
 [dependencies]
 rudf = {path = "../lib", features=["rocksdb"]}