diff --git a/src/ui/windows/mining_controls.cpp b/src/ui/windows/mining_controls.cpp
index 6b266c3..f358881 100644
--- a/src/ui/windows/mining_controls.cpp
+++ b/src/ui/windows/mining_controls.cpp
@@ -143,6 +143,7 @@ void RenderMiningControls(App* app, const WalletState& state, const MiningInfo&
                 auto applyThreads = [&](int tc) {
                     tc = std::clamp(tc, 1, max_threads);
                     if (tc == s_selected_threads) return;
+                    if (s_benchmark.active()) return; // the benchmark owns the thread count while it runs (as the grid)
                     s_selected_threads = tc;          // shown at once; the App applies it ~0.5 s after the last change
                     app->selectMiningThreads(tc);
                 };
@@ -189,7 +190,7 @@ void RenderMiningControls(App* app, const WalletState& state, const MiningInfo&
 
                 // "-" button (disabled at 1 thread)
                 if (rectStepBtn("##ThreadMinus", ICON_MD_REMOVE, sx, TR("mining_threads_minus_tooltip"),
-                                s_selected_threads <= 1))
+                                s_selected_threads <= 1 || s_benchmark.active()))
                     applyThreads(s_selected_threads - 1);
                 sx += sideW + g;
 
@@ -202,15 +203,18 @@ void RenderMiningControls(App* app, const WalletState& state, const MiningInfo&
                 ImGui::SetCursorScreenPos(ImVec2(sx, sy));
                 ImGui::SetNextItemWidth(fieldW);
                 int tc = s_selected_threads;
+                const bool benchLocked = s_benchmark.active();   // read-only while the benchmark runs (as -/+)
+                ImGui::BeginDisabled(benchLocked);
                 if (ImGui::InputInt("##ThreadCountInput", &tc, 0, 0, ImGuiInputTextFlags_EnterReturnsTrue))
                     applyThreads(tc);
                 if (ImGui::IsItemHovered()) material::Tooltip("%s", TR("mining_threads_input_tooltip"));
+                ImGui::EndDisabled();
                 ImGui::PopStyleVar();
                 sx += fieldW + g;
 
                 // "+" button (disabled at max_threads)
                 if (rectStepBtn("##ThreadPlus", ICON_MD_ADD, sx, TR("mining_threads_plus_tooltip"),
-                                s_selected_threads >= max_threads))
+                                s_selected_threads >= max_threads || s_benchmark.active()))
                     applyThreads(s_selected_threads + 1);
 
                 ImGui::SetCursorScreenPos(savedCur);