diff --git a/java/com/google/gerrit/server/project/ProjectCacheImpl.java b/java/com/google/gerrit/server/project/ProjectCacheImpl.java
index 6498d1b..0afaa3f 100644
--- a/java/com/google/gerrit/server/project/ProjectCacheImpl.java
+++ b/java/com/google/gerrit/server/project/ProjectCacheImpl.java
@@ -76,6 +76,7 @@
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
+import java.util.stream.Stream;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.Config;
@@ -300,19 +301,20 @@
   @Override
   public Set<AccountGroup.UUID> guessRelevantGroupUUIDs() {
     try (Timer0.Context ignored = guessRelevantGroupsLatency.start()) {
+      Stream<AccountGroup.UUID> configuredRelevantGroups =
+          Arrays.stream(config.getStringList("groups", /* subsection= */ null, "relevantGroup"))
+              .map(AccountGroup::uuid);
+
+      Stream<AccountGroup.UUID> guessedRelevantGroups =
+          inMemoryProjectCache.asMap().values().stream()
+              .filter(Objects::nonNull)
+              .flatMap(p -> p.getAllGroupUUIDs().stream())
+              // getAllGroupUUIDs shouldn't really return null UUIDs, but harden
+              // against them just in case there is a bug or corner case.
+              .filter(id -> id != null && id.get() != null);
+
       Set<AccountGroup.UUID> relevantGroupUuids =
-          Streams.concat(
-                  Arrays.stream(
-                          config.getStringList("groups", /* subsection= */ null, "relevantGroup"))
-                      .map(AccountGroup::uuid),
-                  all().stream()
-                      .map(n -> inMemoryProjectCache.getIfPresent(n))
-                      .filter(Objects::nonNull)
-                      .flatMap(p -> p.getAllGroupUUIDs().stream())
-                      // getAllGroupUUIDs shouldn't really return null UUIDs, but harden
-                      // against them just in case there is a bug or corner case.
-                      .filter(id -> id != null && id.get() != null))
-              .collect(toSet());
+          Streams.concat(configuredRelevantGroups, guessedRelevantGroups).collect(toSet());
       logger.atFine().log("relevant group UUIDs: %s", relevantGroupUuids);
       return relevantGroupUuids;
     }