diff --git a/category.go b/category.go
index 9e90dd3..f740d3b 100644
--- a/category.go
+++ b/category.go
@@ -34,12 +34,12 @@ func (c *Category) Check() error {
 
 	if c.Scheme != "" {
 		if !isValidURI(c.Scheme) {
-			return fmt.Errorf("scheme attribute of category %v not correctly formatted", c.Scheme)
+			return fmt.Errorf("scheme attribute %v of category not correctly formatted", c.Scheme)
 		}
 	}
 
 	if !isCorrectlyEscaped(c.Label) {
-		return fmt.Errorf("label attribute of category %v not correctly escaped", c.Label)
+		return fmt.Errorf("label attribute %v of category not correctly escaped", c.Label)
 	}
 
 	if c.Content == nil {