diff --git a/src/app/shared/nodes/generic-node/generic-node.html b/src/app/shared/nodes/generic-node/generic-node.html
index 2e61ea5..51dadb1 100644
--- a/src/app/shared/nodes/generic-node/generic-node.html
+++ b/src/app/shared/nodes/generic-node/generic-node.html
@@ -587,7 +587,14 @@
           <option value="static">Static value</option>
           <option value="input">Workflow input</option>
           @if (canTakeGlobalInput()) {
-          <option value="global">From global inputs</option>
+          <!--
+            Kept in place and disabled when the flow declares none, rather than hidden: the same
+            reasoning as the Use default button below, where an option that appears and disappears
+            is one nobody discovers. Selecting it used to lead to a mode that could not be completed.
+          -->
+          <option value="global" [disabled]="!localEditorGlobalInputs.length">
+            From global inputs{{ localEditorGlobalInputs.length ? '' : ' (none declared)' }}
+          </option>
           }
         </select>
         @if (localEditorUseInput) {
@@ -620,6 +627,12 @@
         }
       </div>
       }
+      <!--
+        Hidden in global mode: the value there is the ${{global.x}} the picker above writes, so a
+        second control for the same field could only contradict it - a model picker reading
+        "Select model..." next to a source that says the model comes from a global input.
+      -->
+      @if (!localEditorFromGlobal) {
       <div class="llm-modal-field">
         <label>{{ localEditorLabel }}</label>
         <div class="llm-modal-control-row">
@@ -691,6 +704,7 @@
         <small class="llm-modal-tip">{{ localEditorTip }}</small>
         }
       </div>
+      }
       <div class="llm-modal-actions">
         <button type="button" class="llm-btn llm-btn-ghost" (pointerdown)="$event.stopPropagation()" (click)="closeSimpleParamEditor($event)">Cancel</button>
         <button type="button" class="llm-btn llm-btn-primary" [disabled]="!canSaveLocalEditor()" (pointerdown)="$event.stopPropagation()" (click)="saveSimpleParamEditor($event)">Save</button>
diff --git a/src/app/shared/nodes/generic-node/generic-node.spec.ts b/src/app/shared/nodes/generic-node/generic-node.spec.ts
index 3318cd5..a005a3c 100644
--- a/src/app/shared/nodes/generic-node/generic-node.spec.ts
+++ b/src/app/shared/nodes/generic-node/generic-node.spec.ts
@@ -674,6 +674,44 @@ describe('GenericNodeComponent', () => {
       expect(component.localEditorTip).toBe('Leave empty to take it from a node input.');
     });
 
+    it('knows the choice is unusable when the flow declares no global', async () => {
+      const component = fixture.componentInstance as any;
+      withGlobals([]);
+      await openModelEditor(component);
+
+      // Selecting it used to lead to a mode nothing could complete: an empty picker, a hidden
+      // value, and a Save that stays disabled. The option is left in the list and disabled off
+      // this, so the capability stays discoverable.
+      expect(component.canTakeGlobalInput()).toBe(true);
+      expect(component.localEditorGlobalInputs).toEqual([]);
+    });
+
+    it('knows it is usable as soon as the flow has one', async () => {
+      const component = fixture.componentInstance as any;
+      withGlobals([{ name: 'modelName', type: 'TEXT', multiple: false }]);
+      await openModelEditor(component);
+
+      expect(component.canTakeGlobalInput()).toBe(true);
+      expect(component.localEditorGlobalInputs.map((input: any) => input.name)).toEqual(['modelName']);
+    });
+
+    it('cannot be saved from global mode until a global is picked', async () => {
+      const component = fixture.componentInstance as any;
+      withGlobals([{ name: 'modelName', type: 'TEXT', multiple: false }]);
+      await openModelEditor(component);
+
+      component.onLocalEditorSourceModeChange('global');
+      // Entering the mode starts from nothing chosen, and the value control is hidden there: the
+      // reference the picker writes *is* the value, so there is nothing else to fill in.
+      expect(component.localEditorFromGlobal).toBe(true);
+      expect(component.localEditorValue).toBe('');
+      expect(component.canSaveLocalEditor()).toBe(false);
+
+      component.onLocalEditorGlobalInputChange('modelName');
+      expect(component.localEditorValue).toBe('${{global.modelName}}');
+      expect(component.canSaveLocalEditor()).toBe(true);
+    });
+
     it('labels a global with its type and multiplicity', () => {
       const component = fixture.componentInstance as any;