diff --git a/src/game/creeps.js b/src/game/creeps.js
index fa1238d5..682271ed 100644
--- a/src/game/creeps.js
+++ b/src/game/creeps.js
@@ -98,7 +98,8 @@ exports.make = function(_runtimeData, _intents, _register, _globals) {
                 throw new Error('Could not set creep memory');
             }
             globals.Memory.creeps[this.name] = value;
-        }
+        },
+        configurable: true
     });
 
     Creep.prototype.toString = register.wrapFn(function() {
diff --git a/src/game/flags.js b/src/game/flags.js
index 1469c89c..66ed3b64 100644
--- a/src/game/flags.js
+++ b/src/game/flags.js
@@ -47,7 +47,8 @@ exports.make = function(_runtimeData, _intents, _register, _globals) {
                 throw new Error('Could not set flag memory');
             }
             globals.Memory.flags[this.name] = value;
-        }
+        },
+        configurable: true
     });
 
     Flag.prototype.toString = register.wrapFn(function() {
diff --git a/src/game/rooms.js b/src/game/rooms.js
index b2ee09ba..b484430e 100644
--- a/src/game/rooms.js
+++ b/src/game/rooms.js
@@ -532,7 +532,8 @@ exports.make = function(_runtimeData, _intents, _register, _globals) {
                 throw new Error('Could not set room memory');
             }
             globals.Memory.rooms[this.name] = value;
-        }
+        },
+        configurable: true
     });
 
     Room.prototype.find = register.wrapFn(function(type, opts) {
diff --git a/src/game/structures.js b/src/game/structures.js
index 5df958ae..bf256f51 100644
--- a/src/game/structures.js
+++ b/src/game/structures.js
@@ -912,7 +912,8 @@ exports.make = function(_runtimeData, _intents, _register, _globals) {
                 throw new Error('Could not set spawn memory');
             }
             globals.Memory.spawns[data(this.id).name] = value;
-        }
+        },
+        configurable: true
     });
 
     StructureSpawn.prototype.toString = register.wrapFn(function() {