diff --git a/lix/libstore/gc.cc b/lix/libstore/gc.cc
index 309c30fc6..91ecf0cc3 100644
--- a/lix/libstore/gc.cc
+++ b/lix/libstore/gc.cc
@@ -966,9 +966,9 @@ try {
 
     {
         auto state(_gcState.lock());
+        state->gcWaiters.push_back(std::move(pfp.fulfiller));
 
         if (state->gcRunning) {
-            state->gcWaiters.push_back(std::move(pfp.fulfiller));
             debug("waiting for auto-GC to finish");
             goto sync;
         }
diff --git a/tests/functional/gc-auto.sh b/tests/functional/gc-auto.sh
index 521d9e539..46ae9c4ee 100644
--- a/tests/functional/gc-auto.sh
+++ b/tests/functional/gc-auto.sh
@@ -4,6 +4,13 @@ needLocalStore "“min-free” and “max-free” are daemon options"
 
 clearStore
 
+fake_free=$TEST_ROOT/fake-free
+export _NIX_TEST_FREE_SPACE_FILE=$fake_free
+echo 1100 > $fake_free
+
+# Check that auto-GC during evaluation progresses.
+timeout --signal=KILL 10s nix eval --expr 'builtins.toFile "meow" "meow"' --min-free 2000
+
 garbage1=$(nix store add-path --name garbage1 ./nar-access.sh)
 garbage2=$(nix store add-path --name garbage2 ./nar-access.sh)
 garbage3=$(nix store add-path --name garbage3 ./nar-access.sh)
@@ -11,10 +18,6 @@ garbage3=$(nix store add-path --name garbage3 ./nar-access.sh)
 ls -l $garbage3
 POSIXLY_CORRECT=1 du $garbage3
 
-fake_free=$TEST_ROOT/fake-free
-export _NIX_TEST_FREE_SPACE_FILE=$fake_free
-echo 1100 > $fake_free
-
 fifoLock=$TEST_ROOT/fifoLock
 mkfifo "$fifoLock"