diff --git a/src/Application/Application_MassViewer_Weapons.cpp b/src/Application/Application_MassViewer_Weapons.cpp
index a9e3281..d23a1cd 100644
--- a/src/Application/Application_MassViewer_Weapons.cpp
+++ b/src/Application/Application_MassViewer_Weapons.cpp
@@ -467,8 +467,8 @@ Application::drawWeaponEditor(GameObjects::Weapon& weapon) {
         if(map->find(part.id) != map->cend()) {
             ImGui::TextUnformatted(map->at(part.id).cbegin(), map->at(part.id).cend());
         }
-        else if(part.id == -1) {
-            ImGui::TextUnformatted("<none>");
+        else if(part.id < 0) {
+            ImGui::TextUnformatted("<invalid part ID>");
         }
         else{
             ImGui::Text("ID: %i", part.id);
@@ -498,7 +498,7 @@ Application::drawWeaponEditor(GameObjects::Weapon& weapon) {
 
         ImGui::SameLine();
         if(ImGui::SmallButton("Hide part " ICON_FA_QUESTION_CIRCLE)) {
-            part.id = 96 + (part.id / 100) * 100;
+            part.id = 96 + part.id >= 0 ? (part.id / 100) * 100 : 0;
         }
         drawTooltip(_selectedWeaponPart == 0 ?
                     "This will hide the selected part, but not its accessories. "