diff --git a/Cargo.lock b/Cargo.lock
index 0e113c8..66d2970 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -36,20 +36,4 @@ dependencies = [
  "intaglio",
  "itertools",
  "once_cell",
- "tinyvec",
 ]
-
-[[package]]
-name = "tinyvec"
-version = "1.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87cc5ceb3875bb20c2890005a4e226a4651264a5c75edb2421b52861a0a0cb50"
-dependencies = [
- "tinyvec_macros",
-]
-
-[[package]]
-name = "tinyvec_macros"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"
diff --git a/Cargo.toml b/Cargo.toml
index 2353505..b9e379d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,4 +9,3 @@ edition = "2021"
 intaglio = "1.8.0"
 itertools = "0.10.5"
 once_cell = "1.18.0"
-tinyvec = { version = "1.6.0", features = ["alloc"] }
diff --git a/src/main.rs b/src/main.rs
index b26c80f..04c35b1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,7 +9,6 @@ use std::{
 use intaglio::{Symbol, SymbolTable};
 use itertools::Itertools;
 use once_cell::sync::Lazy;
-use tinyvec::TinyVec;
 
 static TABLE: Lazy<Mutex<SymbolTable>> = Lazy::new(|| Mutex::new(SymbolTable::new()));
 static FORALL: Lazy<Symbol> = Lazy::new(|| TABLE.lock().unwrap().intern("forall").unwrap());
@@ -41,23 +40,15 @@ fn do_it() -> Option<String> {
     ))
 }
 
-type SexpVec = TinyVec<[Sexp; 8]>;
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 enum Sexp {
     Atom(Symbol),
-    List(Box<SexpVec>),
-}
-
-impl Default for Sexp {
-    fn default() -> Self {
-        Self::nil()
-    }
+    List(Vec<Sexp>),
 }
 
 impl Sexp {
     fn nil() -> Self {
-        Self::List(Box::new(TinyVec::new()))
+        Self::List(Vec::new())
     }
 
     /// Returns `true` if the sexp is [`Atom`].
@@ -121,7 +112,7 @@ impl Sexp {
                 out
             }
             Sexp::List(xs) => {
-                let mut out = HashSet::from_iter(xs.iter());
+                let mut out = HashSet::from_iter(xs);
                 out.extend(xs.iter().flat_map(Sexp::concretion_targets));
                 out
             }
@@ -227,7 +218,7 @@ fn at_depth(depth: usize, sexp: &mut Sexp) -> &mut Sexp {
     }
 }
 
-fn parse<'src>(tokens: &'src [Token<'src>]) -> Option<SexpVec> {
+fn parse<'src>(tokens: &'src [Token<'src>]) -> Option<Vec<Sexp>> {
     let mut out = Sexp::nil();
     let mut depth = 0;
 
@@ -251,7 +242,7 @@ fn parse<'src>(tokens: &'src [Token<'src>]) -> Option<SexpVec> {
     }
 
     match out {
-        Sexp::List(xs) => Some(*xs),
+        Sexp::List(xs) => Some(xs),
         Sexp::Atom(_) => unreachable!(),
     }
 }
@@ -415,7 +406,7 @@ fn matches(vars: Option<&Vec<Symbol>>, lhs: &Sexp, expr: &Sexp) -> bool {
         (Sexp::Atom(a), Sexp::Atom(b)) => a == b || is_var(a),
         (Sexp::Atom(a), Sexp::List(_)) => is_var(a),
         (Sexp::List(a), Sexp::List(b)) => {
-            a.len() == b.len() && a.iter().zip(b.iter()).all(|(a, b)| matches(vars, a, b))
+            a.len() == b.len() && a.iter().zip(b).all(|(a, b)| matches(vars, a, b))
         }
         _ => false,
     }
@@ -434,10 +425,7 @@ fn rw(rule: &Rule, sexp: &Sexp) -> Sexp {
             } else {
                 match sexp {
                     Sexp::Atom(_) => sexp.clone(),
-                    Sexp::List(xs) => {
-                        let inner: SexpVec = xs.iter().map(|s| s.rw(rule)).collect();
-                        Sexp::List(Box::new(inner))
-                    }
+                    Sexp::List(xs) => Sexp::List(xs.iter().map(|s| s.rw(rule)).collect()),
                 }
             }
         }
@@ -447,10 +435,7 @@ fn rw(rule: &Rule, sexp: &Sexp) -> Sexp {
             } else {
                 match sexp {
                     Sexp::Atom(_) => sexp.clone(),
-                    Sexp::List(xs) => {
-                        let inner: SexpVec = xs.iter().map(|s| s.rw(rule)).collect();
-                        Sexp::List(Box::new(inner))
-                    }
+                    Sexp::List(xs) => Sexp::List(xs.iter().map(|s| s.rw(rule)).collect()),
                 }
             }
         }