diff --git a/pkg/controller/api/username_check.go b/pkg/controller/api/username_check.go
index 66886d4..410f3ca 100644
--- a/pkg/controller/api/username_check.go
+++ b/pkg/controller/api/username_check.go
@@ -5,6 +5,7 @@ import (
 	"net/http"
 	"strings"
 
+	"code.nonshy.com/nonshy/website/pkg/config"
 	"code.nonshy.com/nonshy/website/pkg/models"
 )
 
@@ -49,6 +50,16 @@ func UsernameCheck() http.HandlerFunc {
 			return
 		}
 
+		// Is it reserved?
+		for _, cmp := range config.ReservedUsernames {
+			if username == cmp {
+				SendJSON(w, http.StatusOK, Response{
+					Error: "That username is reserved, please choose a different username.",
+				})
+				return
+			}
+		}
+
 		// Send success response.
 		SendJSON(w, http.StatusOK, Response{
 			OK: true,