diff --git a/src/hydra-queue-runner/queue-monitor.cc b/src/hydra-queue-runner/queue-monitor.cc
index 49ba7ec6..b7c6ff8d 100644
--- a/src/hydra-queue-runner/queue-monitor.cc
+++ b/src/hydra-queue-runner/queue-monitor.cc
@@ -59,12 +59,17 @@ void State::getQueuedBuilds(Connection & conn, std::shared_ptr<StoreAPI> store,
 
     /* Grab the queued builds from the database, but don't process
        them yet (since we don't want a long-running transaction). */
-    std::multimap<Path, Build::ptr> newBuilds;
+    std::vector<BuildID> newIDs;
+    std::map<BuildID, Build::ptr> newBuildsByID;
+    std::multimap<Path, BuildID> newBuildsByPath;
 
     {
         pqxx::work txn(conn);
 
-        auto res = txn.parameterized("select id, project, jobset, job, drvPath, maxsilent, timeout, timestamp, globalPriority from Builds where id > $1 and finished = 0 order by id")(lastBuildId).exec();
+        auto res = txn.parameterized
+            ("select id, project, jobset, job, drvPath, maxsilent, timeout, timestamp, globalPriority from Builds "
+             "where id > $1 and finished = 0 order by globalPriority desc, id")
+            (lastBuildId).exec();
 
         for (auto const & row : res) {
             auto builds_(builds.lock());
@@ -85,7 +90,9 @@ void State::getQueuedBuilds(Connection & conn, std::shared_ptr<StoreAPI> store,
             build->globalPriority = row["globalPriority"].as<int>();
             build->jobset = createJobset(txn, build->projectName, build->jobsetName);
 
-            newBuilds.emplace(std::make_pair(build->drvPath, build));
+            newIDs.push_back(id);
+            newBuildsByID[id] = build;
+            newBuildsByPath.emplace(std::make_pair(build->drvPath, id));
         }
     }
 
@@ -96,6 +103,7 @@ void State::getQueuedBuilds(Connection & conn, std::shared_ptr<StoreAPI> store,
     createBuild = [&](Build::ptr build) {
         printMsg(lvlTalkative, format("loading build %1% (%2%)") % build->id % build->fullJobName());
         nrAdded++;
+        newBuildsByID.erase(build->id);
 
         if (!store->isValidPath(build->drvPath)) {
             /* Derivation has been GC'ed prematurely. */
@@ -124,13 +132,11 @@ void State::getQueuedBuilds(Connection & conn, std::shared_ptr<StoreAPI> store,
            if build A depends on build B with top-level step X, then X
            will be "accounted" to B in doBuildStep(). */
         for (auto & r : newSteps) {
-            while (true) {
-                auto i = newBuilds.find(r->drvPath);
-                if (i == newBuilds.end()) break;
-                Build::ptr b = i->second;
-                newBuilds.erase(i);
-                createBuild(b);
-            }
+            auto i = newBuildsByPath.find(r->drvPath);
+            if (i == newBuildsByPath.end()) continue;
+            auto j = newBuildsByID.find(i->second);
+            if (j == newBuildsByID.end()) continue;
+            createBuild(j->second);
         }
 
         /* If we didn't get a step, it means the step's outputs are
@@ -219,9 +225,10 @@ void State::getQueuedBuilds(Connection & conn, std::shared_ptr<StoreAPI> store,
     /* Now instantiate build steps for each new build. The builder
        threads can start building the runnable build steps right away,
        even while we're still processing other new builds. */
-    while (!newBuilds.empty()) {
-        auto build = newBuilds.begin()->second;
-        newBuilds.erase(newBuilds.begin());
+    for (auto id : newIDs) {
+        auto i = newBuildsByID.find(id);
+        if (i == newBuildsByID.end()) continue;
+        auto build = i->second;
 
         newRunnable.clear();
         nrAdded = 0;