diff --git a/html5ever/Cargo.toml b/html5ever/Cargo.toml
index 836d20b2..c9ef393d 100644
--- a/html5ever/Cargo.toml
+++ b/html5ever/Cargo.toml
@@ -17,7 +17,6 @@ trace_tokenizer = []
 
 [dependencies]
 log = "0.4"
-mac = "0.1"
 markup5ever = { version = "0.17", path = "../markup5ever" }
 match_token = { workspace = true }
 
diff --git a/html5ever/src/lib.rs b/html5ever/src/lib.rs
index e1415f60..e4200d6b 100644
--- a/html5ever/src/lib.rs
+++ b/html5ever/src/lib.rs
@@ -18,13 +18,12 @@ pub use markup5ever::*;
 
 pub use serialize::serialize;
 
-#[macro_use]
-mod macros;
-
 mod util {
     pub(crate) mod str;
 }
 
+pub(crate) mod macros;
+
 pub mod driver;
 pub mod serialize;
 pub mod tokenizer;
diff --git a/html5ever/src/macros.rs b/html5ever/src/macros.rs
index f38b5cf3..cea6f395 100644
--- a/html5ever/src/macros.rs
+++ b/html5ever/src/macros.rs
@@ -21,13 +21,14 @@ macro_rules! unwrap_or_return {
         x
     }};
 }
+pub(crate) use unwrap_or_return;
 
 macro_rules! time {
     ($e:expr) => {{
-        let now = ::std::time::Instant::now();
+        let t0 = ::std::time::Instant::now();
         let result = $e;
-        let d = now.elapsed();
-        let dt = d.as_secs() * 1_000_000_000 + u64::from(d.subsec_nanos());
+        let dt = t0.elapsed().as_nanos() as u64;
         (result, dt)
     }};
 }
+pub(crate) use time;
diff --git a/html5ever/src/tokenizer/char_ref/mod.rs b/html5ever/src/tokenizer/char_ref/mod.rs
index c97780cc..20842073 100644
--- a/html5ever/src/tokenizer/char_ref/mod.rs
+++ b/html5ever/src/tokenizer/char_ref/mod.rs
@@ -13,8 +13,7 @@ use crate::data;
 use crate::tendril::StrTendril;
 
 use log::debug;
-use mac::format_if;
-use std::borrow::Cow::Borrowed;
+use std::borrow::Cow::{self, Borrowed};
 use std::char::from_u32;
 
 use self::State::*;
@@ -257,12 +256,14 @@ impl CharRefTokenizer {
         };
 
         if error {
-            let msg = format_if!(
-                tokenizer.opts.exact_errors,
-                "Invalid numeric character reference",
-                "Invalid numeric character reference value 0x{:06X}",
-                self.num
-            );
+            let msg = if tokenizer.opts.exact_errors {
+                Cow::from(format!(
+                    "Invalid numeric character reference value 0x{:06X}",
+                    self.num
+                ))
+            } else {
+                Cow::from("Invalid numeric character reference")
+            };
             tokenizer.emit_error(msg);
         }
 
@@ -299,12 +300,11 @@ impl CharRefTokenizer {
     }
 
     fn emit_name_error<Sink: TokenSink>(&mut self, tokenizer: &Tokenizer<Sink>) {
-        let msg = format_if!(
-            tokenizer.opts.exact_errors,
-            "Invalid character reference",
-            "Invalid character reference &{}",
-            self.name_buf()
-        );
+        let msg = if tokenizer.opts.exact_errors {
+            Cow::from(format!("Invalid character reference &{}", self.name_buf()))
+        } else {
+            Cow::from("Invalid character reference")
+        };
         tokenizer.emit_error(msg);
     }
 
diff --git a/html5ever/src/tokenizer/mod.rs b/html5ever/src/tokenizer/mod.rs
index edc42fc8..23d737fb 100644
--- a/html5ever/src/tokenizer/mod.rs
+++ b/html5ever/src/tokenizer/mod.rs
@@ -24,7 +24,6 @@ use self::char_ref::{CharRef, CharRefTokenizer};
 use crate::util::str::lower_ascii_letter;
 
 use log::{debug, trace};
-use mac::format_if;
 use markup5ever::{ns, small_char_set, TokenizerResult};
 use std::borrow::Cow::{self, Borrowed};
 use std::cell::{Cell, RefCell, RefMut};
@@ -32,6 +31,7 @@ use std::collections::BTreeMap;
 use std::mem;
 
 pub use crate::buffer_queue::{BufferQueue, FromSet, NotFromSet, SetResult};
+use crate::macros::{time, unwrap_or_return};
 use crate::tendril::StrTendril;
 use crate::{Attribute, LocalName, QualName, SmallCharSet};
 
@@ -376,13 +376,13 @@ impl<Sink: TokenSink> Tokenizer<Sink> {
         #[cfg(feature = "trace_tokenizer")]
         trace!("  error");
 
-        let msg = format_if!(
-            self.opts.exact_errors,
-            "Bad character",
-            "Saw {} in state {:?}",
-            self.current_char.get(),
-            self.state.get()
-        );
+        let msg = if self.opts.exact_errors {
+            Cow::from("Bad character")
+        } else {
+            let c = self.current_char.get();
+            let state = self.state.get();
+            Cow::from(format!("Saw {c} in state {state:?}"))
+        };
         self.emit_error(msg);
     }
 
@@ -391,12 +391,12 @@ impl<Sink: TokenSink> Tokenizer<Sink> {
         #[cfg(feature = "trace_tokenizer")]
         trace!("  error_eof");
 
-        let msg = format_if!(
-            self.opts.exact_errors,
-            "Unexpected EOF",
-            "Saw EOF in state {:?}",
-            self.state.get()
-        );
+        let msg = if self.opts.exact_errors {
+            Cow::from("Unexpected EOF")
+        } else {
+            let state = self.state.get();
+            Cow::from(format!("Saw EOF in state {state:?}"))
+        };
         self.emit_error(msg);
     }
 
diff --git a/html5ever/src/tree_builder/mod.rs b/html5ever/src/tree_builder/mod.rs
index 3de1e4f7..f0d89b92 100644
--- a/html5ever/src/tree_builder/mod.rs
+++ b/html5ever/src/tree_builder/mod.rs
@@ -22,7 +22,7 @@ use crate::tokenizer;
 use crate::tokenizer::states as tok_state;
 use crate::tokenizer::{Doctype, EndTag, StartTag, Tag, TokenSink, TokenSinkResult};
 
-use std::borrow::Cow::Borrowed;
+use std::borrow::Cow::{self, Borrowed};
 use std::cell::{Cell, Ref, RefCell};
 use std::collections::VecDeque;
 use std::iter::{Enumerate, Rev};
@@ -32,7 +32,6 @@ use crate::tokenizer::states::RawKind;
 use crate::tree_builder::tag_sets::*;
 use crate::util::str::to_escaped_string;
 use log::{debug, log_enabled, warn, Level};
-use mac::format_if;
 use markup5ever::{expanded_name, local_name, namespace_prefix, ns};
 
 #[macro_use]
@@ -488,12 +487,11 @@ where
                 if self.mode.get() == InsertionMode::Initial {
                     let (err, quirk) = data::doctype_error_and_quirks(&dt, self.opts.iframe_srcdoc);
                     if err {
-                        self.sink.parse_error(format_if!(
-                            self.opts.exact_errors,
-                            "Bad DOCTYPE",
-                            "Bad DOCTYPE: {:?}",
-                            dt
-                        ));
+                        self.sink.parse_error(if self.opts.exact_errors {
+                            Cow::from(format!("Bad DOCTYPE: {dt:?}"))
+                        } else {
+                            Cow::from("Bad DOCTYPE")
+                        });
                     }
                     let Doctype {
                         name,
@@ -513,12 +511,11 @@ where
                     self.mode.set(InsertionMode::BeforeHtml);
                     return tokenizer::TokenSinkResult::Continue;
                 } else {
-                    self.sink.parse_error(format_if!(
-                        self.opts.exact_errors,
-                        "DOCTYPE in body",
-                        "DOCTYPE in insertion mode {:?}",
-                        self.mode.get()
-                    ));
+                    self.sink.parse_error(if self.opts.exact_errors {
+                        Cow::from(format!("DOCTYPE in insertion mode {:?}", self.mode.get()))
+                    } else {
+                        Cow::from("DOCTYPE in body")
+                    });
                     return tokenizer::TokenSinkResult::Continue;
                 }
             },
@@ -618,13 +615,15 @@ where
     Sink: TreeSink<Handle = Handle>,
 {
     fn unexpected<T: fmt::Debug>(&self, _thing: &T) -> ProcessResult<Handle> {
-        self.sink.parse_error(format_if!(
-            self.opts.exact_errors,
-            "Unexpected token",
-            "Unexpected token {} in insertion mode {:?}",
-            to_escaped_string(_thing),
-            self.mode.get()
-        ));
+        self.sink.parse_error(if self.opts.exact_errors {
+            Cow::from(format!(
+                "Unexpected token {} in insertion mode {:?}",
+                to_escaped_string(_thing),
+                self.mode.get()
+            ))
+        } else {
+            Cow::from("Unexpected token")
+        });
         ProcessResult::Done
     }
 
@@ -1053,20 +1052,19 @@ where
             "thead" "tr" "body" "html");
 
         for elem in self.open_elems.borrow().iter() {
-            let error;
-            {
+            let error = {
                 let elem_name = self.sink.elem_name(elem);
                 let name = elem_name.expanded();
                 if body_end_ok(name) {
                     continue;
                 }
-                error = format_if!(
-                    self.opts.exact_errors,
-                    "Unexpected open tag at end of body",
-                    "Unexpected open tag {:?} at end of body",
-                    name
-                );
-            }
+
+                if self.opts.exact_errors {
+                    Cow::from(format!("Unexpected open tag {name:?} at end of body"))
+                } else {
+                    Cow::from("Unexpected open tag at end of body")
+                }
+            };
             self.sink.parse_error(error);
             // FIXME: Do we keep checking after finding one bad tag?
             // The spec suggests not.
@@ -1193,12 +1191,11 @@ where
     /// Signal an error if it was not the first one.
     fn expect_to_close(&self, name: LocalName) {
         if self.pop_until_named(name.clone()) != 1 {
-            self.sink.parse_error(format_if!(
-                self.opts.exact_errors,
-                "Unexpected open element",
-                "Unexpected open element while closing {:?}",
-                name
-            ));
+            self.sink.parse_error(if self.opts.exact_errors {
+                Cow::from(format!("Unexpected open element while closing {name:?}"))
+            } else {
+                Cow::from("Unexpected open element")
+            });
         }
     }
 
@@ -1242,12 +1239,14 @@ where
             self.orig_mode.set(Some(self.mode.get()));
             ProcessResult::Reprocess(InsertionMode::InTableText, token)
         } else {
-            self.sink.parse_error(format_if!(
-                self.opts.exact_errors,
-                "Unexpected characters in table",
-                "Unexpected characters {} in table",
-                to_escaped_string(&token)
-            ));
+            self.sink.parse_error(if self.opts.exact_errors {
+                Cow::from(format!(
+                    "Unexpected characters {} in table",
+                    to_escaped_string(&token)
+                ))
+            } else {
+                Cow::from("Unexpected characters in table")
+            });
             self.foster_parent_in_body(token)
         }
     }
@@ -1553,15 +1552,11 @@ where
             }
         }
 
-        // Can't use unwrap_or_return!() due to rust-lang/rust#16617.
-        let match_idx = match match_idx {
-            None => {
-                // I believe this is impossible, because the root
-                // <html> element is in special_tag.
-                self.unexpected(&tag);
-                return;
-            },
-            Some(x) => x,
+        let Some(match_idx) = match_idx else {
+            // I believe this is impossible, because the root
+            // <html> element is in special_tag.
+            self.unexpected(&tag);
+            return;
         };
 
         self.generate_implied_end_except(tag.name.clone());
diff --git a/html5ever/src/tree_builder/rules.rs b/html5ever/src/tree_builder/rules.rs
index 68ccadac..e3326ff0 100644
--- a/html5ever/src/tree_builder/rules.rs
+++ b/html5ever/src/tree_builder/rules.rs
@@ -491,13 +491,9 @@ where
 
                 </form> => {
                     if !self.in_html_elem_named(local_name!("template")) {
-                        // Can't use unwrap_or_return!() due to rust-lang/rust#16617.
-                        let node = match self.form_elem.take() {
-                            None => {
-                                self.sink.parse_error(Borrowed("Null form element pointer on </form>"));
-                                return ProcessResult::Done;
-                            }
-                            Some(x) => x,
+                        let Some(node) = self.form_elem.take() else {
+                            self.sink.parse_error(Borrowed("Null form element pointer on </form>"));
+                            return ProcessResult::Done;
                         };
                         if !self.in_scope(default_scope, |n| self.sink.same_node(&node, &n)) {
                             self.sink.parse_error(Borrowed("Form element not in scope on </form>"));
diff --git a/html5ever/src/util/str.rs b/html5ever/src/util/str.rs
index 2c0ec3e2..9d788365 100644
--- a/html5ever/src/util/str.rs
+++ b/html5ever/src/util/str.rs
@@ -29,14 +29,24 @@ pub(crate) fn lower_ascii_letter(c: char) -> Option<char> {
 #[allow(non_snake_case)]
 mod test {
     use super::lower_ascii_letter;
-    use mac::test_eq;
-
-    test_eq!(lower_letter_a_is_a, lower_ascii_letter('a'), Some('a'));
-    test_eq!(lower_letter_A_is_a, lower_ascii_letter('A'), Some('a'));
-    test_eq!(lower_letter_symbol_is_None, lower_ascii_letter('!'), None);
-    test_eq!(
-        lower_letter_nonascii_is_None,
-        lower_ascii_letter('\u{a66e}'),
-        None
-    );
+
+    #[test]
+    fn lower_letter_a_is_a() {
+        assert_eq!(lower_ascii_letter('a'), Some('a'));
+    }
+
+    #[test]
+    fn lower_letter_A_is_a() {
+        assert_eq!(lower_ascii_letter('A'), Some('a'));
+    }
+
+    #[test]
+    fn lower_letter_symbol_is_None() {
+        assert_eq!(lower_ascii_letter('!'), None);
+    }
+
+    #[test]
+    fn lower_letter_nonascii_is_None() {
+        assert_eq!(lower_ascii_letter('\u{a66e}'), None);
+    }
 }
diff --git a/xml5ever/Cargo.toml b/xml5ever/Cargo.toml
index e7bbfb8f..0194ac37 100644
--- a/xml5ever/Cargo.toml
+++ b/xml5ever/Cargo.toml
@@ -19,7 +19,6 @@ trace_tokenizer = []
 
 [dependencies]
 log = "0.4"
-mac = "0.1"
 markup5ever = { version = "0.17", path = "../markup5ever" }
 
 [dev-dependencies]
diff --git a/xml5ever/src/lib.rs b/xml5ever/src/lib.rs
index 9d7d2557..c9e557ff 100644
--- a/xml5ever/src/lib.rs
+++ b/xml5ever/src/lib.rs
@@ -35,14 +35,7 @@
 
 pub use markup5ever::*;
 
-macro_rules! time {
-    ($e:expr) => {{
-        let t0 = ::std::time::Instant::now();
-        let result = $e;
-        let dt = t0.elapsed().as_nanos() as u64;
-        (result, dt)
-    }};
-}
+pub(crate) mod macros;
 
 /// Driver
 pub mod driver;
diff --git a/xml5ever/src/macros.rs b/xml5ever/src/macros.rs
new file mode 100644
index 00000000..cea6f395
--- /dev/null
+++ b/xml5ever/src/macros.rs
@@ -0,0 +1,34 @@
+// Copyright 2014-2017 The html5ever Project Developers. See the
+// COPYRIGHT file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+macro_rules! unwrap_or_return {
+    ($opt:expr) => {{
+        let Some(x) = $opt else {
+            return;
+        };
+        x
+    }};
+    ($opt:expr, $retval:expr) => {{
+        let Some(x) = $opt else {
+            return $retval;
+        };
+        x
+    }};
+}
+pub(crate) use unwrap_or_return;
+
+macro_rules! time {
+    ($e:expr) => {{
+        let t0 = ::std::time::Instant::now();
+        let result = $e;
+        let dt = t0.elapsed().as_nanos() as u64;
+        (result, dt)
+    }};
+}
+pub(crate) use time;
diff --git a/xml5ever/src/tokenizer/char_ref/mod.rs b/xml5ever/src/tokenizer/char_ref/mod.rs
index 84e5e70f..1a515c40 100644
--- a/xml5ever/src/tokenizer/char_ref/mod.rs
+++ b/xml5ever/src/tokenizer/char_ref/mod.rs
@@ -9,11 +9,11 @@
 
 use super::{TokenSink, XmlTokenizer};
 use crate::data;
+use crate::macros::unwrap_or_return;
 use crate::tendril::StrTendril;
 use log::debug;
-use mac::{format_if, unwrap_or_return};
 use markup5ever::buffer_queue::BufferQueue;
-use std::borrow::Cow::Borrowed;
+use std::borrow::Cow::{self, Borrowed};
 use std::char::from_u32;
 
 use self::State::*;
@@ -258,12 +258,14 @@ impl CharRefTokenizer {
         };
 
         if error {
-            let msg = format_if!(
-                tokenizer.opts.exact_errors,
-                "Invalid numeric character reference",
-                "Invalid numeric character reference value 0x{:06X}",
-                self.num
-            );
+            let msg = if tokenizer.opts.exact_errors {
+                Cow::from(format!(
+                    "Invalid numeric character reference value 0x{:06X}",
+                    self.num
+                ))
+            } else {
+                Cow::from("Invalid numeric character reference")
+            };
             tokenizer.emit_error(msg);
         }
 
@@ -295,12 +297,11 @@ impl CharRefTokenizer {
     }
 
     fn emit_name_error<Sink: TokenSink>(&mut self, tokenizer: &XmlTokenizer<Sink>) {
-        let msg = format_if!(
-            tokenizer.opts.exact_errors,
-            "Invalid character reference",
-            "Invalid character reference &{}",
-            self.name_buf()
-        );
+        let msg = if tokenizer.opts.exact_errors {
+            Cow::from(format!("Invalid character reference &{}", self.name_buf()))
+        } else {
+            Cow::from("Invalid character reference")
+        };
         tokenizer.emit_error(msg);
     }
 
diff --git a/xml5ever/src/tokenizer/mod.rs b/xml5ever/src/tokenizer/mod.rs
index 22cacba5..e69e45e5 100644
--- a/xml5ever/src/tokenizer/mod.rs
+++ b/xml5ever/src/tokenizer/mod.rs
@@ -17,10 +17,10 @@ pub use self::interface::{
 };
 pub use crate::{LocalName, Namespace, Prefix};
 
+use crate::macros::{time, unwrap_or_return};
 use crate::tendril::StrTendril;
 use crate::{buffer_queue, Attribute, QualName, SmallCharSet};
 use log::debug;
-use mac::{format_if, unwrap_or_return};
 use markup5ever::{local_name, namespace_prefix, ns, small_char_set, TokenizerResult};
 use std::borrow::Cow::{self, Borrowed};
 use std::cell::{Cell, RefCell, RefMut};
@@ -233,7 +233,7 @@ impl<Sink: TokenSink> XmlTokenizer<Sink> {
         if self.ignore_lf.get() {
             self.ignore_lf.set(false);
             if c == '\n' {
-                c = unwrap_or_return!(input.next(), None);
+                c = input.next()?;
             }
         }
 
@@ -265,12 +265,11 @@ impl<Sink: TokenSink> XmlTokenizer<Sink> {
     }
 
     fn bad_eof_error(&self) {
-        let msg = format_if!(
-            self.opts.exact_errors,
-            "Unexpected EOF",
-            "Saw EOF in state {:?}",
-            self.state
-        );
+        let msg = if self.opts.exact_errors {
+            Cow::from(format!("Saw EOF in state {:?}", self.state))
+        } else {
+            Cow::from("Unexpected EOF")
+        };
         self.emit_error(msg);
     }
 
@@ -365,13 +364,13 @@ impl<Sink: TokenSink> XmlTokenizer<Sink> {
     }
 
     fn bad_char_error(&self) {
-        let msg = format_if!(
-            self.opts.exact_errors,
-            "Bad character",
-            "Saw {} in state {:?}",
-            self.current_char.get(),
-            self.state.get()
-        );
+        let msg = if self.opts.exact_errors {
+            let c = self.current_char.get();
+            let state = self.state.get();
+            Cow::from(format!("Saw {c} in state {state:?}"))
+        } else {
+            Cow::from("Bad character")
+        };
         self.emit_error(msg);
     }
 
diff --git a/xml5ever/src/tree_builder/mod.rs b/xml5ever/src/tree_builder/mod.rs
index 059956d2..1f672ad6 100644
--- a/xml5ever/src/tree_builder/mod.rs
+++ b/xml5ever/src/tree_builder/mod.rs
@@ -10,7 +10,6 @@
 mod types;
 
 use log::{debug, warn};
-use mac::unwrap_or_return;
 use markup5ever::{local_name, namespace_prefix, ns};
 use std::borrow::Cow;
 use std::borrow::Cow::Borrowed;
@@ -24,6 +23,7 @@ pub use self::interface::{ElemName, NodeOrText, Tracer, TreeSink};
 use self::types::*;
 use crate::interface::{self, create_element, AppendNode, Attribute, QualName};
 use crate::interface::{AppendText, ExpandedName};
+use crate::macros::unwrap_or_return;
 use crate::tokenizer::{self, EndTag, ProcessResult, StartTag, Tag, TokenSink};
 use crate::tokenizer::{Doctype, EmptyTag, Pi, ShortTag};
 use crate::{LocalName, Namespace, Prefix};