diff --git a/src/aff.rs b/src/aff.rs
index 2850cae..96bfcf7 100644
--- a/src/aff.rs
+++ b/src/aff.rs
@@ -57,8 +57,7 @@ pub(crate) struct Condition {
     /// over it directly to attempt to match the pattern.
     ///
     /// This string is non-empty.
-    // TODO: Box<str>?
-    pattern: String,
+    pattern: Box<str>,
     /// The number of `char`s that the pattern describes.
     ///
     /// `Condition` is such a small subset of regex that we can tell only from a linear scan of
@@ -124,9 +123,9 @@ pub(crate) struct Affix<K> {
     /// a prefix and a suffix, both the prefix and suffix should have `crossproduct: true`.
     pub crossproduct: bool,
     /// What is stripped from the stem when the affix is applied.
-    pub strip: Option<String>,
+    pub strip: Option<Box<str>>,
     /// What should be added when the affix is applied.
-    pub add: String,
+    pub add: Box<str>,
     /// Condition that the stem should be checked against to query if the affix is relevant.
     ///
     /// This is optional in Spellbook. Hunspell and Nuspell represent what we say is `None` as
@@ -155,8 +154,8 @@ impl<K: AffixKind> Affix<K> {
         Ok(Self {
             flag,
             crossproduct,
-            strip: strip.map(|str| str.to_string()),
-            add: add.to_string(),
+            strip: strip.map(|str| str.into()),
+            add: add.into(),
             flags,
             condition,
             phantom_data: PhantomData,
@@ -263,7 +262,7 @@ impl Prefix {
     /// This function `expect`s that the `Prefix`'s `add` is a prefix of the input `word`.
     pub fn to_stem<'a>(&self, word: &'a str) -> Cow<'a, str> {
         let stripped = word
-            .strip_prefix(&self.add)
+            .strip_prefix(&*self.add)
             .expect("to_stem should only be called when the `add` is a prefix of the word");
 
         match &self.strip {
@@ -290,11 +289,11 @@ impl Prefix {
     pub fn to_derived(&self, word: &str) -> String {
         let stripped = match &self.strip {
             Some(strip) => word
-                .strip_prefix(strip)
+                .strip_prefix(&**strip)
                 .expect("to_derived should only be called when `strip` is a prefix of the word"),
             None => word,
         };
-        let mut stem = self.add.clone();
+        let mut stem = self.add.to_string();
         stem.push_str(stripped);
         stem
     }
@@ -326,7 +325,7 @@ impl Suffix {
     /// This function `expect`s that the `Suffix`'s `add` is a suffix of the input `word`.
     pub fn to_stem<'a>(&self, word: &'a str) -> Cow<'a, str> {
         let stripped = word
-            .strip_suffix(&self.add)
+            .strip_suffix(&*self.add)
             .expect("to_stem should only be called when the `add` is a suffix of the word");
 
         match self.strip.as_deref() {
@@ -353,7 +352,7 @@ impl Suffix {
     pub fn to_derived(&self, word: &str) -> String {
         let mut stem = match &self.strip {
             Some(strip) => word
-                .strip_suffix(strip)
+                .strip_suffix(&**strip)
                 .expect("to_derived should only be called when `strip` is a prefix of the word"),
             None => word,
         }
@@ -1218,7 +1217,7 @@ pub(crate) struct AffData {
     pub suffixes: SuffixIndex,
     pub break_table: BreakTable,
     pub compound_rules: CompoundRuleTable,
-    pub compound_syllable_vowels: String,
+    pub compound_syllable_vowels: Box<str>,
     pub compound_patterns: Box<[CompoundPattern]>,
     pub input_conversions: ConversionTable,
     pub output_conversions: ConversionTable,
@@ -1228,7 +1227,7 @@ pub(crate) struct AffData {
     pub similarities: Box<[SimilarityGroup]>,
     // phonetic_table: PhoneticTable,
     pub ignore_chars: Box<[char]>,
-    pub keyboard_closeness: String,
+    pub keyboard_closeness: Box<str>,
     pub try_chars: Box<str>,
     pub options: AffOptions,
     // Parsing options. These are preserved so that we can re-use them in `Dictionary::add`.
@@ -1511,7 +1510,7 @@ mod test {
 
         let prefixes: Vec<_> = index
             .affixes_of("asdfg")
-            .map(|prefix| prefix.add.as_str())
+            .map(|prefix| prefix.add.as_ref())
             .collect();
 
         assert_eq!(&["", "", "a", "as", "as", "asdf"], prefixes.as_slice());
@@ -1533,7 +1532,7 @@ mod test {
 
         let suffixes: Vec<_> = index
             .affixes_of("ahahuub")
-            .map(|suffix| suffix.add.as_str())
+            .map(|suffix| suffix.add.as_ref())
             .collect();
 
         assert_eq!(
diff --git a/src/aff/parser.rs b/src/aff/parser.rs
index 44e1223..9d65962 100644
--- a/src/aff/parser.rs
+++ b/src/aff/parser.rs
@@ -212,11 +212,11 @@ pub(crate) fn parse<'aff, 'dic, S: BuildHasher + Clone>(
     if !cx.ignore_chars.is_empty() {
         for prefix in cx.prefixes.iter_mut() {
             let add = erase_chars(&prefix.add, &cx.ignore_chars);
-            prefix.add = add.into_owned();
+            prefix.add = add.into();
         }
         for suffix in cx.suffixes.iter_mut() {
             let add = erase_chars(&suffix.add, &cx.ignore_chars);
-            suffix.add = add.into_owned();
+            suffix.add = add.into();
         }
     }
 
@@ -230,10 +230,10 @@ pub(crate) fn parse<'aff, 'dic, S: BuildHasher + Clone>(
         input_conversions: cx.input_conversions.into(),
         output_conversions: cx.output_conversions.into(),
         compound_rules: cx.compound_rules.into(),
-        compound_syllable_vowels: cx.compound_syllable_vowels.to_string(),
+        compound_syllable_vowels: cx.compound_syllable_vowels.into(),
         compound_patterns: cx.compound_patterns.into(),
         ignore_chars: cx.ignore_chars.into(),
-        keyboard_closeness: cx.keyboard_closeness.to_string(),
+        keyboard_closeness: cx.keyboard_closeness.into(),
         try_chars: cx.try_chars.into(),
         options: cx.options,
         flag_type: cx.flag_type,
@@ -1791,7 +1791,7 @@ impl FromStr for Condition {
         }
 
         Ok(Self {
-            pattern: String::from(s),
+            pattern: s.into(),
             chars,
         })
     }
@@ -1897,28 +1897,28 @@ mod test {
         );
         assert_eq!(
             Ok(Condition {
-                pattern: "foo".to_string(),
+                pattern: "foo".into(),
                 chars: 3
             }),
             "foo".parse()
         );
         assert_eq!(
             Ok(Condition {
-                pattern: "foo[bar]".to_string(),
+                pattern: "foo[bar]".into(),
                 chars: 4
             }),
             "foo[bar]".parse()
         );
         assert_eq!(
             Ok(Condition {
-                pattern: "[foo]bar".to_string(),
+                pattern: "[foo]bar".into(),
                 chars: 4
             }),
             "[foo]bar".parse()
         );
         assert_eq!(
             Ok(Condition {
-                pattern: "foo[bar]baz".to_string(),
+                pattern: "foo[bar]baz".into(),
                 chars: 7
             }),
             "foo[bar]baz".parse()
diff --git a/src/suggester/ngram.rs b/src/suggester/ngram.rs
index f2c417e..add7271 100644
--- a/src/suggester/ngram.rs
+++ b/src/suggester/ngram.rs
@@ -359,14 +359,14 @@ impl<'a, S: BuildHasher> Suggester<'a, S> {
             if suffix
                 .strip
                 .as_ref()
-                .is_some_and(|suf| !stem.as_str().ends_with(suf))
+                .is_some_and(|suf| !stem.as_str().ends_with(&**suf))
             {
                 continue;
             }
             if !suffix.condition_matches(stem.as_str()) {
                 continue;
             }
-            if !suffix.add.is_empty() && !word.ends_with(&suffix.add) {
+            if !suffix.add.is_empty() && !word.ends_with(&*suffix.add) {
                 continue;
             }
 
@@ -398,14 +398,14 @@ impl<'a, S: BuildHasher> Suggester<'a, S> {
                 if prefix
                     .strip
                     .as_ref()
-                    .is_some_and(|pre| !suffixed_stem.starts_with(pre))
+                    .is_some_and(|pre| !suffixed_stem.starts_with(&**pre))
                 {
                     continue;
                 }
                 if !prefix.condition_matches(suffixed_stem) {
                     continue;
                 }
-                if !prefix.add.is_empty() && !word.starts_with(&prefix.add) {
+                if !prefix.add.is_empty() && !word.starts_with(&*prefix.add) {
                     continue;
                 }
 
@@ -430,14 +430,14 @@ impl<'a, S: BuildHasher> Suggester<'a, S> {
             if prefix
                 .strip
                 .as_ref()
-                .is_some_and(|pre| !stem.as_str().starts_with(pre))
+                .is_some_and(|pre| !stem.as_str().starts_with(&**pre))
             {
                 continue;
             }
             if !prefix.condition_matches(stem.as_str()) {
                 continue;
             }
-            if !prefix.add.is_empty() && !word.starts_with(&prefix.add) {
+            if !prefix.add.is_empty() && !word.starts_with(&*prefix.add) {
                 continue;
             }