diff --git a/src/hydra-eval-jobs/hydra-eval-jobs.cc b/src/hydra-eval-jobs/hydra-eval-jobs.cc
index acffe1d1..44a273a9 100644
--- a/src/hydra-eval-jobs/hydra-eval-jobs.cc
+++ b/src/hydra-eval-jobs/hydra-eval-jobs.cc
@@ -504,6 +504,17 @@ int main(int argc, char * * argv)
 
             job.erase("namedConstituents");
 
+            /* Register the derivation as a GC root.  !!! This
+                registers roots for jobs that we may have already
+                done. */
+            auto localStore = store.dynamic_pointer_cast<LocalFSStore>();
+            if (gcRootsDir != "" && localStore) {
+                auto drvPath = job["drvPath"].get<std::string>();
+                Path root = gcRootsDir + "/" + std::string(baseNameOf(drvPath));
+                if (!pathExists(root))
+                    localStore->addPermRoot(localStore->parseStorePath(drvPath), root);
+            }
+
             if (!brokenJobs.empty()) {
                 std::stringstream ss;
                 for (const auto& [jobName, error] : brokenJobs) {
diff --git a/t/evaluate-basic.t b/t/evaluator/evaluate-basic.t
similarity index 100%
rename from t/evaluate-basic.t
rename to t/evaluator/evaluate-basic.t
diff --git a/t/evaluator/evaluate-constituents-gc.t b/t/evaluator/evaluate-constituents-gc.t
new file mode 100644
index 00000000..a9b23e6c
--- /dev/null
+++ b/t/evaluator/evaluate-constituents-gc.t
@@ -0,0 +1,20 @@
+use strict;
+use warnings;
+use Setup;
+use Test2::V0;
+
+my $ctx = test_context();
+
+my $builds = $ctx->makeAndEvaluateJobset(
+    expression => 'constituents.nix',
+);
+
+my $constituentA = $builds->{"constituentA"};
+my $directAggregate = $builds->{"direct_aggregate"};
+my $indirectAggregate = $builds->{"indirect_aggregate"};
+
+is(system('nix-store', '--delete', $constituentA->drvpath), 256, "Deleting a constituent derivation fails");
+is(system('nix-store', '--delete', $directAggregate->drvpath), 256, "Deleting the direct aggregate derivation fails");
+is(system('nix-store', '--delete', $indirectAggregate->drvpath), 256, "Deleting the indirect aggregate derivation fails");
+
+done_testing;
diff --git a/t/evaluate-dependent-jobsets.t b/t/evaluator/evaluate-dependent-jobsets.t
similarity index 100%
rename from t/evaluate-dependent-jobsets.t
rename to t/evaluator/evaluate-dependent-jobsets.t
diff --git a/t/jobs/constituents.nix b/t/jobs/constituents.nix
new file mode 100644
index 00000000..5b7106b9
--- /dev/null
+++ b/t/jobs/constituents.nix
@@ -0,0 +1,40 @@
+with import ./config.nix;
+rec {
+  constituentA = mkDerivation {
+    name = "empty-dir-A";
+    builder = ./empty-dir-builder.sh;
+  };
+
+  constituentB = mkDerivation {
+    name = "empty-dir-B";
+    builder = ./empty-dir-builder.sh;
+  };
+
+  direct_aggregate = mkDerivation {
+    name = "direct_aggregate";
+    _hydraAggregate = true;
+    constituents = [
+      constituentA
+    ];
+    builder = ./empty-dir-builder.sh;
+  };
+
+  indirect_aggregate = mkDerivation {
+    name = "indirect_aggregate";
+    _hydraAggregate = true;
+    constituents = [
+      "constituentA"
+    ];
+    builder = ./empty-dir-builder.sh;
+  };
+
+  mixed_aggregate = mkDerivation {
+    name = "mixed_aggregate";
+    _hydraAggregate = true;
+    constituents = [
+      "constituentA"
+      constituentB
+    ];
+    builder = ./empty-dir-builder.sh;
+  };
+}
diff --git a/t/queue-runner/direct-indirect-constituents.t b/t/queue-runner/direct-indirect-constituents.t
new file mode 100644
index 00000000..35370450
--- /dev/null
+++ b/t/queue-runner/direct-indirect-constituents.t
@@ -0,0 +1,35 @@
+use strict;
+use warnings;
+use Setup;
+use Test2::V0;
+
+my $ctx = test_context();
+
+my $builds = $ctx->makeAndEvaluateJobset(
+    expression => 'constituents.nix',
+);
+
+my $constituentBuildA = $builds->{"constituentA"};
+my $constituentBuildB = $builds->{"constituentB"};
+
+my $eval = $constituentBuildA->jobsetevals->first();
+is($eval->evaluationerror->errormsg, "");
+
+subtest "Verifying the direct aggregate" => sub {
+    my $aggBuild = $builds->{"direct_aggregate"};
+    is($aggBuild->constituents->first()->id, $constituentBuildA->id, "The ID of the constituent is correct");
+};
+
+subtest "Verifying the indirect aggregate" => sub {
+    my $indirectBuild = $builds->{"indirect_aggregate"};
+    is($indirectBuild->constituents->first()->id, $constituentBuildA->id, "The ID of the constituent is correct");
+};
+
+subtest "Verifying a mix of direct and indirect aggregate references" => sub {
+    my $mixedBuild = $builds->{"mixed_aggregate"};
+    my ($constituentA, $constituentB) = $mixedBuild->constituents()->search({}, {order_by => { -asc => "job"} });
+    is($constituentA->id, $constituentBuildA->id, "The ID of the constituent is correct");
+    is($constituentB->id, $constituentBuildB->id, "The ID of the constituent is correct");
+};
+
+done_testing;