diff --git a/common/place/placer_heap.cc b/common/place/placer_heap.cc
index fa71c796..2ed2cdeb 100644
--- a/common/place/placer_heap.cc
+++ b/common/place/placer_heap.cc
@@ -177,7 +177,7 @@ class HeAPPlacer
     {
         auto startt = std::chrono::high_resolution_clock::now();
 
-        std::lock_guard<Context> lock{*ctx};
+        std::unique_lock<Context> lock{*ctx};
         place_constraints();
         build_fast_bels();
         alloc_control_sets();
@@ -396,7 +396,7 @@ class HeAPPlacer
         }
 
         ctx->check();
-        lock.unlock_early();
+        lock.unlock();
 
 #if !defined(NPNR_DISABLE_THREADS)
         if (cfg.parallelRefine) {
diff --git a/common/route/router2.cc b/common/route/router2.cc
index e3e553c0..5a737b13 100644
--- a/common/route/router2.cc
+++ b/common/route/router2.cc
@@ -1680,7 +1680,7 @@ struct Router2
         ThreadContext st;
         int iter = 1;
 
-        std::lock_guard<Context> lock{*ctx};
+        std::unique_lock<Context> lock{*ctx};
 
         for (size_t i = 0; i < nets_by_udata.size(); i++)
             route_queue.push_back(i);
@@ -1797,7 +1797,7 @@ struct Router2
 
         log_info("Running router1 to check that route is legal...\n");
 
-        lock.unlock_early();
+        lock.unlock();
 
         router1(ctx, Router1Cfg(ctx));
     }