diff --git a/include/config.h b/include/config.h
index 80e1cc2b..7d87e34f 100644
--- a/include/config.h
+++ b/include/config.h
@@ -89,7 +89,7 @@ public:
         return this->data_dir;
     }
 
-    std::string get_log_dir() {
+    std::string get_log_dir() const {
         return this->log_dir;
     }
 
@@ -121,7 +121,7 @@ public:
         return this->ssl_certificate_key;
     }
 
-    std::string get_config_file() {
+    std::string get_config_file() const {
         return config_file;
     }