diff --git a/asset_server_resize/templates/asset_server_resize/index.html b/asset_server_resize/templates/asset_server_resize/index.html
index a59a44b21f4cf24365be534a213f38c7e8bc18f3..5eaee920f605802d5cd2df3b483b6e4860c3bdcc 100644
--- a/asset_server_resize/templates/asset_server_resize/index.html
+++ b/asset_server_resize/templates/asset_server_resize/index.html
@@ -44,6 +44,7 @@
                         id="height"
                         name="height"
                         type="number"
+                        min="0"
                         class="text-input form-field__control"
                         placeholder="Výška"
                     >
@@ -51,6 +52,7 @@
                         id="width"
                         name="width"
                         type="number"
+                        min="0"
                         class="text-input form-field__control"
                         placeholder="Ĺ Ă­rka"
                     >