diff --git a/src/main/js/main.js b/src/main/js/main.js
index 60481f7..cd2c568 100644
--- a/src/main/js/main.js
+++ b/src/main/js/main.js
@@ -28,7 +28,7 @@ doAfterLoad(() => {
 
     const debreviate = () => {
         clearFormValidity(debreviateForm);
-        const abbreviation = abbreviationInput.value.trim();
+        const abbreviation = abbreviationInput.value.trim().toLowerCase();
         if (abbreviation === "") {
             showInputInvalid(abbreviationInput, "Abbreviation should be non-empty.");
             return;