diff --git a/src/routes/generatedImages.js b/src/routes/generatedImages.js
index 2c27f39c..ad24dff7 100644
--- a/src/routes/generatedImages.js
+++ b/src/routes/generatedImages.js
@@ -167,6 +167,17 @@ router.put('/admin/image-settings/:workflow', adminMiddleware, async (req, res)
     if (!IMAGE_WORKFLOWS.includes(workflow)) throw images.failure(404, 'Workflow not found');
     const budget = images.budgetLimit(req.body.budget);
 
+    // The primary model — the field this endpoint used to accept and drop, so a
+    // saved selection never survived a refresh. Blank is a real value for
+    // my_resources ("use the Clinical Assistant's model"), so an empty string is
+    // written rather than skipped, and only an absent field leaves it alone.
+    let model = null;
+    if (req.body.model !== undefined) {
+      const id = String(req.body.model || '').trim();
+      if (id && !MODEL_ID.test(id)) throw images.failure(400, 'Not a model ID: ' + id.slice(0, 60));
+      model = id;
+    }
+
     // Fallbacks are optional, and only sent when the caller means to change
     // them: an absent field leaves the saved chain alone rather than clearing it.
     let fallbacks = null;
@@ -178,8 +189,10 @@ router.put('/admin/image-settings/:workflow', adminMiddleware, async (req, res)
         if (!MODEL_ID.test(id)) throw images.failure(400, 'Not a model ID: ' + id.slice(0, 60));
       }
       // The primary counts toward the cap, and naming it again would pay twice
-      // for the same refusal.
-      const primary = String(await db.getSetting(workflow + '.image_model') || '');
+      // for the same refusal. Compare against the model this request is setting,
+      // not the one it replaces, or a model promoted to primary in the same save
+      // survives as its own fallback.
+      const primary = model !== null ? model : String(await db.getSetting(workflow + '.image_model') || '');
       fallbacks = fallbacks.filter((id, i) => id !== primary && fallbacks.indexOf(id) === i);
       if (fallbacks.length > images.MAX_IMAGE_MODELS - 1) {
         throw images.failure(400, 'At most ' + (images.MAX_IMAGE_MODELS - 1) +
@@ -191,6 +204,7 @@ router.put('/admin/image-settings/:workflow', adminMiddleware, async (req, res)
     try {
       await client.query('BEGIN');
       const changes = { image_budget: budget };
+      if (model !== null) changes.image_model = model;
       if (fallbacks !== null) changes.fallback_image_models = fallbacks.join(',');
       for (const [key, value] of Object.entries(changes)) {
         await client.query('INSERT INTO app_settings(key,value) VALUES($1,$2) ON CONFLICT(key) DO UPDATE SET value=$2,updated_at=NOW()', [workflow + '.' + key, String(value)]);