diff --git a/pkg/core/storage/memcached_store.go b/pkg/core/storage/memcached_store.go
index fc5daba3b..1958bab5e 100644
--- a/pkg/core/storage/memcached_store.go
+++ b/pkg/core/storage/memcached_store.go
@@ -75,7 +75,7 @@ func (s *MemCachedStore) GetBatch() *MemBatch {
 func (s *MemCachedStore) Seek(key []byte, f func(k, v []byte)) {
 	s.mut.RLock()
 	defer s.mut.RUnlock()
-	s.MemoryStore.Seek(key, f)
+	s.MemoryStore.seek(key, f)
 	s.ps.Seek(key, func(k, v []byte) {
 		elem := string(k)
 		// If it's in mem, we already called f() for it in MemoryStore.Seek().
diff --git a/pkg/core/storage/memory_store.go b/pkg/core/storage/memory_store.go
index 30ba21e26..7238e0a42 100644
--- a/pkg/core/storage/memory_store.go
+++ b/pkg/core/storage/memory_store.go
@@ -97,6 +97,13 @@ func (s *MemoryStore) PutBatch(batch Batch) error {
 
 // Seek implements the Store interface.
 func (s *MemoryStore) Seek(key []byte, f func(k, v []byte)) {
+	s.mut.RLock()
+	s.seek(key, f)
+	s.mut.RUnlock()
+}
+
+// seek is an internal unlocked implementation of Seek.
+func (s *MemoryStore) seek(key []byte, f func(k, v []byte)) {
 	for k, v := range s.mem {
 		if strings.HasPrefix(k, string(key)) {
 			f([]byte(k), v)