diff --git a/include/collection_manager.h b/include/collection_manager.h
index 0d2d7648..ce8cdb9a 100644
--- a/include/collection_manager.h
+++ b/include/collection_manager.h
@@ -71,7 +71,7 @@ public:
 
     bool auth_key_matches(std::string auth_key_sent);
 
-    bool search_only_auth_key_matches(std::string auth_key_sent);
+    bool search_only_auth_key_matches(const std::string & auth_key_sent);
 
     Option<Collection*> create_collection(const std::string name, const std::vector<field> & fields,
                                           const std::string & default_sorting_field,
diff --git a/src/collection_manager.cpp b/src/collection_manager.cpp
index d3ff8e3b..8c070dc0 100644
--- a/src/collection_manager.cpp
+++ b/src/collection_manager.cpp
@@ -200,8 +200,8 @@ bool CollectionManager::auth_key_matches(std::string auth_key_sent) {
     return (auth_key == auth_key_sent);
 }
 
-bool CollectionManager::search_only_auth_key_matches(std::string auth_key_sent) {
-    return (search_only_auth_key == auth_key_sent);
+bool CollectionManager::search_only_auth_key_matches(const std::string & auth_key_sent) {
+    return !auth_key_sent.empty() && (search_only_auth_key == auth_key_sent);
 }
 
 Option<Collection*> CollectionManager::create_collection(const std::string name, const std::vector<field> & fields,