diff --git a/src/syntax/ast.rs b/src/syntax/ast.rs
index af7fedce9..97c8940d9 100644
--- a/src/syntax/ast.rs
+++ b/src/syntax/ast.rs
@@ -29,7 +29,7 @@ pub trait AstNode: Sized {
 
 macro_rules! node {
     ($(#[$attr:meta])* $name:ident) => {
-        #[derive(Debug, Default, Clone, PartialEq, Hash)]
+        #[derive(Debug, Default, Clone, Hash)]
         #[repr(transparent)]
         $(#[$attr])*
         pub struct $name(SyntaxNode);
@@ -73,7 +73,7 @@ impl Markup {
 }
 
 /// An expression in markup, math or code.
-#[derive(Debug, Clone, PartialEq, Hash)]
+#[derive(Debug, Clone, Hash)]
 pub enum Expr {
     /// Plain text without markup.
     Text(Text),
@@ -1055,7 +1055,7 @@ impl Array {
 }
 
 /// An item in an array.
-#[derive(Debug, Clone, PartialEq, Hash)]
+#[derive(Debug, Clone, Hash)]
 pub enum ArrayItem {
     /// A bare expression: `12`.
     Pos(Expr),
@@ -1092,7 +1092,7 @@ impl Dict {
 }
 
 /// An item in an dictionary expresssion.
-#[derive(Debug, Clone, PartialEq, Hash)]
+#[derive(Debug, Clone, Hash)]
 pub enum DictItem {
     /// A named pair: `thickness: 3pt`.
     Named(Named),
@@ -1452,7 +1452,7 @@ impl Args {
 }
 
 /// An argument to a function call.
-#[derive(Debug, Clone, PartialEq, Hash)]
+#[derive(Debug, Clone, Hash)]
 pub enum Arg {
     /// A positional argument: `12`.
     Pos(Expr),
@@ -1509,7 +1509,7 @@ impl Closure {
 }
 
 /// A parameter to a closure.
-#[derive(Debug, Clone, PartialEq, Hash)]
+#[derive(Debug, Clone, Hash)]
 pub enum Param {
     /// A positional parameter: `x`.
     Pos(Ident),
@@ -1724,7 +1724,7 @@ impl ModuleImport {
 }
 
 /// The items that ought to be imported from a file.
-#[derive(Debug, Clone, PartialEq, Hash)]
+#[derive(Debug, Clone, Hash)]
 pub enum Imports {
     /// All items in the scope of the file should be imported.
     Wildcard,
diff --git a/src/syntax/node.rs b/src/syntax/node.rs
index e153b0bf2..e216d3c9e 100644
--- a/src/syntax/node.rs
+++ b/src/syntax/node.rs
@@ -9,11 +9,11 @@ use crate::diag::SourceError;
 use crate::util::EcoString;
 
 /// A node in the untyped syntax tree.
-#[derive(Clone, PartialEq, Hash)]
+#[derive(Clone, Eq, PartialEq, Hash)]
 pub struct SyntaxNode(Repr);
 
 /// The three internal representations.
-#[derive(Clone, PartialEq, Hash)]
+#[derive(Clone, Eq, PartialEq, Hash)]
 enum Repr {
     /// A leaf node.
     Leaf(LeafNode),
@@ -147,6 +147,15 @@ impl SyntaxNode {
                 .collect()
         }
     }
+
+    /// Set a synthetic span for the node and all its descendants.
+    pub fn synthesize(&mut self, span: Span) {
+        match &mut self.0 {
+            Repr::Leaf(leaf) => leaf.span = span,
+            Repr::Inner(inner) => Arc::make_mut(inner).synthesize(span),
+            Repr::Error(error) => Arc::make_mut(error).span = span,
+        }
+    }
 }
 
 impl SyntaxNode {
@@ -174,15 +183,6 @@ impl SyntaxNode {
         *self = SyntaxNode::error(message, text, ErrorPos::Full);
     }
 
-    /// Set a synthetic span for the node and all its descendants.
-    pub(crate) fn synthesize(&mut self, span: Span) {
-        match &mut self.0 {
-            Repr::Leaf(leaf) => leaf.span = span,
-            Repr::Inner(inner) => Arc::make_mut(inner).synthesize(span),
-            Repr::Error(error) => Arc::make_mut(error).span = span,
-        }
-    }
-
     /// Assign spans to each node.
     pub(super) fn numberize(
         &mut self,
@@ -212,7 +212,7 @@ impl SyntaxNode {
     }
 
     /// Whether this is a leaf node.
-    pub(crate) fn is_leaf(&self) -> bool {
+    pub(super) fn is_leaf(&self) -> bool {
         matches!(self.0, Repr::Leaf(_))
     }
 
@@ -291,7 +291,7 @@ impl Default for SyntaxNode {
 }
 
 /// A leaf node in the untyped syntax tree.
-#[derive(Clone, Hash)]
+#[derive(Clone, Eq, PartialEq, Hash)]
 struct LeafNode {
     /// What kind of node this is (each kind would have its own struct in a
     /// strongly typed AST).
@@ -322,14 +322,8 @@ impl Debug for LeafNode {
     }
 }
 
-impl PartialEq for LeafNode {
-    fn eq(&self, other: &Self) -> bool {
-        self.kind == other.kind && self.text == other.text
-    }
-}
-
 /// An inner node in the untyped syntax tree.
-#[derive(Clone, Hash)]
+#[derive(Clone, Eq, PartialEq, Hash)]
 struct InnerNode {
     /// What kind of node this is (each kind would have its own struct in a
     /// strongly typed AST).
@@ -378,6 +372,7 @@ impl InnerNode {
     /// Set a synthetic span for the node and all its descendants.
     fn synthesize(&mut self, span: Span) {
         self.span = span;
+        self.upper = span.number();
         for child in &mut self.children {
             child.synthesize(span);
         }
@@ -573,18 +568,8 @@ impl Debug for InnerNode {
     }
 }
 
-impl PartialEq for InnerNode {
-    fn eq(&self, other: &Self) -> bool {
-        self.kind == other.kind
-            && self.len == other.len
-            && self.descendants == other.descendants
-            && self.erroneous == other.erroneous
-            && self.children == other.children
-    }
-}
-
 /// An error node in the untyped syntax tree.
-#[derive(Clone, Hash)]
+#[derive(Clone, Eq, PartialEq, Hash)]
 struct ErrorNode {
     /// The error message.
     message: EcoString,
@@ -623,12 +608,6 @@ impl Debug for ErrorNode {
     }
 }
 
-impl PartialEq for ErrorNode {
-    fn eq(&self, other: &Self) -> bool {
-        self.message == other.message && self.text == other.text && self.pos == other.pos
-    }
-}
-
 /// Where in a node an error should be annotated,
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub enum ErrorPos {
diff --git a/src/syntax/reparser.rs b/src/syntax/reparser.rs
index a876e86b5..75a5cc279 100644
--- a/src/syntax/reparser.rs
+++ b/src/syntax/reparser.rs
@@ -213,16 +213,18 @@ fn next_nesting(node: &SyntaxNode, nesting: &mut usize) {
 mod tests {
     use std::ops::Range;
 
-    use super::super::{parse, Source};
+    use super::super::{parse, Source, Span};
 
     #[track_caller]
     fn test(prev: &str, range: Range<usize>, with: &str, incremental: bool) {
         let mut source = Source::detached(prev);
         let prev = source.root().clone();
         let range = source.edit(range, with);
-        let found = source.root();
-        let expected = parse(source.text());
-        if found != &expected {
+        let mut found = source.root().clone();
+        let mut expected = parse(source.text());
+        found.synthesize(Span::detached());
+        expected.synthesize(Span::detached());
+        if found != expected {
             eprintln!("source:   {:?}", source.text());
             eprintln!("previous: {prev:#?}");
             eprintln!("expected: {expected:#?}");
diff --git a/src/syntax/source.rs b/src/syntax/source.rs
index 63509dc88..f00d779b9 100644
--- a/src/syntax/source.rs
+++ b/src/syntax/source.rs
@@ -406,6 +406,8 @@ mod tests {
 
     #[test]
     fn test_source_file_edit() {
+        // This tests only the non-parser parts. The reparsing itself is
+        // tested separately.
         #[track_caller]
         fn test(prev: &str, range: Range<usize>, with: &str, after: &str) {
             let mut source = Source::detached(prev);
@@ -413,7 +415,6 @@ mod tests {
             source.edit(range, with);
             assert_eq!(source.text, result.text);
             assert_eq!(source.lines, result.lines);
-            assert_eq!(*source.root, *result.root);
         }
 
         // Test inserting at the begining.
diff --git a/tests/src/tests.rs b/tests/src/tests.rs
index b90abceeb..8895ccdd0 100644
--- a/tests/src/tests.rs
+++ b/tests/src/tests.rs
@@ -16,7 +16,7 @@ use typst::doc::{Document, Element, Frame, Meta};
 use typst::font::{Font, FontBook};
 use typst::geom::{Abs, RgbaColor, Sides, Smart};
 use typst::model::{func, Library, Value};
-use typst::syntax::{Source, SourceId, SyntaxNode};
+use typst::syntax::{Source, SourceId, Span, SyntaxNode};
 use typst::util::{Buffer, PathExt};
 use typst::World;
 use typst_library::layout::PageNode;
@@ -591,11 +591,21 @@ fn test_reparse(text: &str, i: usize, rng: &mut LinearShift) -> bool {
         incr_source.edit(replace.clone(), with);
 
         let edited_src = incr_source.text();
-        let incr_root = incr_source.root();
         let ref_source = Source::detached(edited_src);
-        let ref_root = ref_source.root();
-        let mut ok = incr_root == ref_root;
-        if !ok {
+        let mut ref_root = ref_source.root().clone();
+        let mut incr_root = incr_source.root().clone();
+
+        // Ensures that the span numbering invariants hold.
+        let spans_ok = test_spans(&ref_root) && test_spans(&incr_root);
+
+        // Remove all spans so that the comparison works out.
+        let tree_ok = {
+            ref_root.synthesize(Span::detached());
+            incr_root.synthesize(Span::detached());
+            ref_root == incr_root
+        };
+
+        if !tree_ok {
             println!(
                 "    Subtest {i} reparse differs from clean parse when inserting '{with}' at {}-{} ❌\n",
                 replace.start, replace.end,
@@ -605,9 +615,7 @@ fn test_reparse(text: &str, i: usize, rng: &mut LinearShift) -> bool {
             println!("    Full source ({}):\n\"{edited_src:?}\"", edited_src.len());
         }
 
-        ok &= test_spans(ref_root);
-        ok &= test_spans(incr_root);
-        ok
+        spans_ok && tree_ok
     };
 
     let mut pick = |range: Range<usize>| {