diff --git a/README.md b/README.md
index 29d614b..5f10c9f 100644
--- a/README.md
+++ b/README.md
@@ -45,6 +45,9 @@ fn main() {
     assert_eq!(inflection::singularize("bookshelves"), "bookshelf");
     assert_eq!(inflection::singularize("merry-go-rounds"), "merry-go-round");
     assert_eq!(inflection::singularize("post offices"), "post office");
+    assert_eq!(inflection::singularize("spectra"), "spectrum");
+    assert_eq!(inflection::singularize("matrices"), "matrix");
+    assert_eq!(inflection::singularize("taxa"), "taxon");
 }
 ```
 
@@ -88,6 +91,9 @@ fn main() {
     assert_eq!(inflection::pluralize("bookshelf"), "bookshelves");
     assert_eq!(inflection::pluralize("merry-go-round"), "merry-go-rounds");
     assert_eq!(inflection::pluralize("post office"), "post offices");
+    assert_eq!(inflection::pluralize("spectrum"), "spectra");
+    assert_eq!(inflection::pluralize("matrix"), "matrices");
+    assert_eq!(inflection::pluralize("taxon"), "taxa");
 }
 ```
 
diff --git a/src/lib.rs b/src/lib.rs
index d80c785..db35a23 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -295,6 +295,8 @@ lazy_static! {
         add_irregular(&mut plurals, &mut singulars, "slice".to_string(), "slices".to_string());
         add_irregular(&mut plurals, &mut singulars, "cactus".to_string(), "cacti".to_string());
         add_irregular(&mut plurals, &mut singulars, "buzz".to_string(), "buzzes".to_string());
+        add_irregular(&mut plurals, &mut singulars, "spectrum".to_string(), "spectra".to_string());
+        add_irregular(&mut plurals, &mut singulars, "taxon".to_string(), "taxa".to_string());
 
         let plurals: Vec<(Regex, String)> = plurals
             .into_iter()