diff --git a/lib/rules/definition-case.js b/lib/rules/definition-case.js
index 01c396fc..5923bc8e 100644
--- a/lib/rules/definition-case.js
+++ b/lib/rules/definition-case.js
@@ -57,7 +57,7 @@ function definitionCase(ast, file, preferred, done) {
         label = contents.slice(start, end).match(LABEL)[1];
 
         if (label !== label.toLowerCase()) {
-            file.warn('Do not use uppper-case characters in definition labels', node);
+            file.warn('Do not use upper-case characters in definition labels', node);
         }
     }