diff --git a/components/reasoning-workspace.jsx b/components/reasoning-workspace.jsx
index 1c95534..dc37be8 100644
--- a/components/reasoning-workspace.jsx
+++ b/components/reasoning-workspace.jsx
@@ -393,12 +393,13 @@ function FocusedQuestionBody({
 
 // ── Persistent navigation controls (overlay-level, outside content grid) ──
 
-function FocusedWorkspaceNavigation({ nodeId, doneForNow, isDoneForNowActive }) {
-  const canDoneForNow = Boolean(isDoneForNowActive);
+function FocusedWorkspaceNavigation({ nodeId, doneForNow, isDoneForNowActive, isProcessing }) {
+  const canDoneForNow = Boolean(isDoneForNowActive) && !isProcessing;
   return (
     <div className="mt-6 flex items-center justify-end border-t border-gray-200 pt-5">
       <button
         onClick={(e) => { e.stopPropagation(); doneForNow?.(); }}
+        disabled={canDoneForNow ? false : true}
         style={{ cursor: canDoneForNow ? "pointer" : "not-allowed" }}
         className={`rounded-lg border px-4 py-2 text-sm font-medium transition whitespace-nowrap ${canDoneForNow ? 'border-gray-300 bg-white text-gray-600 hover:bg-gray-50' : 'border-gray-100 bg-gray-50 text-gray-300'}`}
       >
@@ -2168,6 +2169,7 @@ export default function ReasoningWorkspace({
                         <FocusedWorkspaceNavigation
                           nodeId={focusedPresentationItemId}
                           doneForNow={() => {
+                            if (processingStep === "active") return;
                             /* ── v0.49 — promote eligible focused findings into Current Understanding ─── */
                             onSummaryUpdate?.(focusedPresentationItemId);
                             setDoneForNowIds((prev) => [...prev, focusedPresentationItemId]);
@@ -2177,6 +2179,7 @@ export default function ReasoningWorkspace({
                             setIsFocusedWorkspaceOpen(false);
                           }}
                           isDoneForNowActive={Boolean(getFocusedInvestigation()?.question?.trim())}
+                          isProcessing={processingStep === "active"}
                         />
                       )}
                     </>