diff --git a/compiler/benches/run-cek.rs b/compiler/benches/run-cek.rs
index c69d0c7..16f27ee 100644
--- a/compiler/benches/run-cek.rs
+++ b/compiler/benches/run-cek.rs
@@ -1,6 +1,6 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use homer_compiler::*;
-use std::sync::Arc;
+use std::rc::Rc;
 use std::time::Duration;
 
 const ADDRESS_VAR: &str = "HOMER_BENCH";
@@ -24,8 +24,8 @@ pub fn criterion_benchmark(c: &mut Criterion) {
 
     let db = &mut build::CompilerDB::new();
     let uri = build::Uri::new("bench.doh");
-    let input = Arc::new(std::fs::read_to_string(std::path::Path::new(path)).unwrap());
-    db.set_input(uri, Arc::clone(&input));
+    let input = Rc::new(std::fs::read_to_string(std::path::Path::new(path)).unwrap());
+    db.set_input(uri, Rc::clone(&input));
     let mut success = true;
     db.with_diagnostics(uri, |diagnostics| {
         for diagnostic in diagnostics {
diff --git a/compiler/src/ast/debug.rs b/compiler/src/ast/debug.rs
index 9f22e03..6b4864f 100644
--- a/compiler/src/ast/debug.rs
+++ b/compiler/src/ast/debug.rs
@@ -135,7 +135,7 @@ macro_rules! derive_fmt_debug {
     ($type_name:ident) => {
         impl std::fmt::Debug for $type_name {
             fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-                crate::ast::DebugWriter::fmt(self, f)
+                $crate::ast::DebugWriter::fmt(self, f)
             }
         }
     };
diff --git a/compiler/src/bin/homer-ide.rs b/compiler/src/bin/homer-ide.rs
index 642cab0..b3f7db3 100644
--- a/compiler/src/bin/homer-ide.rs
+++ b/compiler/src/bin/homer-ide.rs
@@ -1,5 +1,5 @@
 use std::error::Error;
-use std::sync::Arc;
+use std::rc::Rc;
 
 use log::info;
 use lsp_server::{Connection, Message, Response};
@@ -123,7 +123,7 @@ impl Server {
     fn validate_document(&mut self, lsp_uri: Url, input: String, print_module: bool) -> Result<()> {
         let uri = build::Uri::new(lsp_uri.as_str());
         info!("Received text for {:?}", uri);
-        self.db.set_input(uri, Arc::new(input));
+        self.db.set_input(uri, Rc::new(input));
 
         let diagnostics: Vec<_> = self.db.with_diagnostics(uri, |diagnostics| {
             diagnostics.map(homer_compiler::diagnostic::Diagnostic::to_lsp).collect()
@@ -225,7 +225,7 @@ impl Server {
         };
         let notification = lsp_server::Notification::new(
             ShowMessage::METHOD.to_owned(),
-            serde_json::to_value(&message_params)?,
+            serde_json::to_value(message_params)?,
         );
         if let Err(error) = self.connection.sender.send(Message::from(notification)) {
             info!("Failed to send message: {:?}", error);
@@ -288,6 +288,7 @@ impl Server {
         }
     }
 
+    #[allow(clippy::type_complexity)]
     fn dispatch_request<R: Request>(
         &self,
         request: lsp_server::Request,
diff --git a/compiler/src/bin/homer-run.rs b/compiler/src/bin/homer-run.rs
index 3c50a65..648ec2c 100644
--- a/compiler/src/bin/homer-run.rs
+++ b/compiler/src/bin/homer-run.rs
@@ -1,5 +1,5 @@
 use homer_compiler::{build, cek, syntax};
-use std::sync::Arc;
+use std::rc::Rc;
 
 #[allow(clippy::iter_nth_zero)]
 fn run() -> std::io::Result<bool> {
@@ -10,8 +10,8 @@ fn run() -> std::io::Result<bool> {
     };
     let db = &mut build::CompilerDB::new();
     let uri = build::Uri::new(&path);
-    let input = Arc::new(std::fs::read_to_string(path)?);
-    db.set_input(uri, Arc::clone(&input));
+    let input = Rc::new(std::fs::read_to_string(path)?);
+    db.set_input(uri, Rc::clone(&input));
 
     let mut success = true;
     db.with_diagnostics(uri, |diagnostics| {
diff --git a/compiler/src/build.rs b/compiler/src/build.rs
index 45cc9bb..2f266a2 100644
--- a/compiler/src/build.rs
+++ b/compiler/src/build.rs
@@ -2,7 +2,7 @@ use crate::{anf, checker, diagnostic, syntax};
 use checker::SymbolInfo;
 use diagnostic::Diagnostic;
 use std::fmt;
-use std::sync::Arc;
+use std::rc::Rc;
 use syntax::Module;
 
 #[derive(Copy, Clone, Eq, Hash, PartialEq)]
@@ -24,24 +24,24 @@ impl fmt::Debug for Uri {
     }
 }
 
-type CheckedModuleOutcome = (Option<Arc<Module>>, Arc<Vec<SymbolInfo>>, Arc<Vec<Diagnostic>>);
+type CheckedModuleOutcome = (Option<Rc<Module>>, Rc<Vec<SymbolInfo>>, Rc<Vec<Diagnostic>>);
 
 #[salsa::query_group(CompilerStorage)]
 trait Compiler: salsa::Database {
     #[salsa::input]
-    fn input(&self, uri: Uri) -> Arc<String>;
+    fn input(&self, uri: Uri) -> Rc<String>;
 
-    fn parsed_module(&self, uri: Uri) -> (Option<Arc<Module>>, Arc<Vec<Diagnostic>>);
+    fn parsed_module(&self, uri: Uri) -> (Option<Rc<Module>>, Rc<Vec<Diagnostic>>);
 
     fn checked_module(&self, uri: Uri) -> CheckedModuleOutcome;
 
-    fn anf_module(&self, uri: Uri) -> Option<Arc<anf::Module>>;
+    fn anf_module(&self, uri: Uri) -> Option<Rc<anf::Module>>;
 }
 
-fn parsed_module(db: &dyn Compiler, uri: Uri) -> (Option<Arc<Module>>, Arc<Vec<Diagnostic>>) {
+fn parsed_module(db: &dyn Compiler, uri: Uri) -> (Option<Rc<Module>>, Rc<Vec<Diagnostic>>) {
     let input = db.input(uri);
     let (opt_parsed_module, diagnostics) = Module::parse(&input);
-    (opt_parsed_module.map(Arc::new), Arc::new(diagnostics))
+    (opt_parsed_module.map(Rc::new), Rc::new(diagnostics))
 }
 
 fn checked_module(db: &dyn Compiler, uri: Uri) -> CheckedModuleOutcome {
@@ -52,11 +52,11 @@ fn checked_module(db: &dyn Compiler, uri: Uri) -> CheckedModuleOutcome {
             Ok((checked_module, symbols)) => (Some(checked_module), symbols, vec![]),
         },
     };
-    (opt_checked_module.map(Arc::new), Arc::new(symbols), Arc::new(diagnostics))
+    (opt_checked_module.map(Rc::new), Rc::new(symbols), Rc::new(diagnostics))
 }
 
-fn anf_module(db: &dyn Compiler, uri: Uri) -> Option<Arc<anf::Module>> {
-    db.checked_module(uri).0.map(|checked_module| Arc::new(checked_module.to_anf()))
+fn anf_module(db: &dyn Compiler, uri: Uri) -> Option<Rc<anf::Module>> {
+    db.checked_module(uri).0.map(|checked_module| Rc::new(checked_module.to_anf()))
 }
 
 #[salsa::database(CompilerStorage)]
@@ -74,19 +74,19 @@ impl CompilerDB {
         Self { storage: salsa::Storage::default() }
     }
 
-    pub fn set_input(&mut self, uri: Uri, input: Arc<String>) {
+    pub fn set_input(&mut self, uri: Uri, input: Rc<String>) {
         (self as &mut dyn Compiler).set_input(uri, input);
     }
 
-    pub fn checked_module(&self, uri: Uri) -> Option<Arc<Module>> {
+    pub fn checked_module(&self, uri: Uri) -> Option<Rc<Module>> {
         (self as &dyn Compiler).checked_module(uri).0
     }
 
-    pub fn symbols(&self, uri: Uri) -> Arc<Vec<SymbolInfo>> {
+    pub fn symbols(&self, uri: Uri) -> Rc<Vec<SymbolInfo>> {
         (self as &dyn Compiler).checked_module(uri).1
     }
 
-    pub fn anf_module(&self, uri: Uri) -> Option<Arc<anf::Module>> {
+    pub fn anf_module(&self, uri: Uri) -> Option<Rc<anf::Module>> {
         (self as &dyn Compiler).anf_module(uri)
     }
 
diff --git a/compiler/src/tests/anf.rs b/compiler/src/tests/anf.rs
index 5cf0b58..05da845 100644
--- a/compiler/src/tests/anf.rs
+++ b/compiler/src/tests/anf.rs
@@ -1,10 +1,10 @@
 use crate::build::*;
-use std::sync::Arc;
+use std::rc::Rc;
 
 fn anf_output(input: &str) -> String {
     let db = &mut CompilerDB::new();
     let uri = Uri::new("foo.homer");
-    db.set_input(uri, Arc::new(input.to_owned()));
+    db.set_input(uri, Rc::new(input.to_owned()));
     assert!(db.with_diagnostics(uri, |diagnostics| diagnostics.next().is_none()));
     format!("{:#?}", db.anf_module(uri).unwrap())
 }
diff --git a/compiler/src/tests/build.rs b/compiler/src/tests/build.rs
index 31f5a4d..3d8ce43 100644
--- a/compiler/src/tests/build.rs
+++ b/compiler/src/tests/build.rs
@@ -1,11 +1,11 @@
 use crate::build::*;
-use std::sync::Arc;
+use std::rc::Rc;
 
 fn build_output(input: &str) -> String {
     use std::fmt::Write;
     let db = &mut CompilerDB::new();
     let uri = Uri::new("foo.homer");
-    db.set_input(uri, Arc::new(input.to_owned()));
+    db.set_input(uri, Rc::new(input.to_owned()));
 
     let mut output = String::new();
     match db.anf_module(uri) {
diff --git a/compiler/src/tests/cek.rs b/compiler/src/tests/cek.rs
index fe938b9..b534945 100644
--- a/compiler/src/tests/cek.rs
+++ b/compiler/src/tests/cek.rs
@@ -1,5 +1,5 @@
 use crate::*;
-use std::sync::Arc;
+use std::rc::Rc;
 
 fn with_cek_result<R, F>(main: &str, input: &str, f: F) -> R
 where
@@ -7,7 +7,7 @@ where
 {
     let db = &mut build::CompilerDB::new();
     let uri = build::Uri::new("test.doh");
-    db.set_input(uri, Arc::new(input.to_string()));
+    db.set_input(uri, Rc::new(input.to_string()));
 
     assert_eq!(0, db.with_diagnostics(uri, |diagnostics| diagnostics.count()));
     let module = db.anf_module(uri).expect("module could not be compiled");