diff --git a/Resources/Locale/en-US/nuke/nuke-core-container.ftl b/Resources/Locale/en-US/nuke/nuke-core-container.ftl
index 47ea15a8316..bbed978bd7e 100644
--- a/Resources/Locale/en-US/nuke/nuke-core-container.ftl
+++ b/Resources/Locale/en-US/nuke/nuke-core-container.ftl
@@ -1,2 +1,3 @@
 nuke-core-container-whitelist-fail-popup = That doesn't fit into the container.
 nuke-core-container-sealed-popup = The {$container} is sealed shut!
+nuke-core-container-closed-fail-popup = You need to open the container first!
diff --git a/Resources/Prototypes/Entities/Objects/Misc/plutonium_core.yml b/Resources/Prototypes/Entities/Objects/Misc/plutonium_core.yml
index 67910888871..bd2a0d871a9 100644
--- a/Resources/Prototypes/Entities/Objects/Misc/plutonium_core.yml
+++ b/Resources/Prototypes/Entities/Objects/Misc/plutonium_core.yml
@@ -47,6 +47,7 @@
         whitelist:
           tags:
           - PlutoniumCore
+        lockedFailPopup: nuke-core-container-closed-fail-popup
         whitelistFailPopup: nuke-core-container-whitelist-fail-popup
   - type: GenericVisualizer
     visuals: