diff --git a/VERSION b/VERSION
index 1b386a5..2016ec3 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-6.18.0
+6.18.1
diff --git a/play-life-web/package.json b/play-life-web/package.json
index cf827ee..d1eaee6 100644
--- a/play-life-web/package.json
+++ b/play-life-web/package.json
@@ -1,6 +1,6 @@
 {
   "name": "play-life-web",
-  "version": "6.18.0",
+  "version": "6.18.1",
   "type": "module",
   "scripts": {
     "dev": "vite",
diff --git a/play-life-web/src/components/ShoppingItemDetail.jsx b/play-life-web/src/components/ShoppingItemDetail.jsx
index 8d1dd9d..6489348 100644
--- a/play-life-web/src/components/ShoppingItemDetail.jsx
+++ b/play-life-web/src/components/ShoppingItemDetail.jsx
@@ -185,7 +185,8 @@ function ShoppingItemDetail({ itemId, onClose, onRefresh, onItemCompleted, onNav
                       type="button"
                       className="progression-control-btn progression-control-minus"
                       onClick={() => {
-                        const current = parseFloat(volumeValue) || 0
+                        const base = item.last_volume ?? item.volume_base ?? 1
+                        const current = volumeValue.trim() ? parseFloat(volumeValue) : base
                         const step = item.volume_base || 1
                         setVolumeValue((current - step).toString())
                       }}
diff --git a/play-life-web/src/components/TaskDetail.jsx b/play-life-web/src/components/TaskDetail.jsx
index 552e4e4..5ae77a2 100644
--- a/play-life-web/src/components/TaskDetail.jsx
+++ b/play-life-web/src/components/TaskDetail.jsx
@@ -829,7 +829,8 @@ function TaskDetail({ taskId, onClose, onRefresh, onTaskCompleted, onNavigate })
                         type="button"
                         className="progression-control-btn progression-control-minus"
                         onClick={() => {
-                          const current = parseFloat(progressionValue) || 0
+                          const base = task.progression_base ?? 1
+                          const current = progressionValue.trim() ? parseFloat(progressionValue) : base
                           const step = task.progression_base || 1
                           setProgressionValue((current - step).toString())
                         }}