diff --git a/Dockerfile b/Dockerfile
index 1636cf0..03533e4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -17,6 +17,7 @@ RUN \
     php7-posix \
     php7-fpm \
     php7-session \
+    php7-mbstring \
     tar
 RUN ln -sf /usr/bin/php7 /usr/bin/php
 
diff --git a/install-db.php b/install-db.php
index 66945e4..f5db417 100644
--- a/install-db.php
+++ b/install-db.php
@@ -13,9 +13,9 @@ foreach ($lines as $line) {
 
     if (!$res) {
       print_notice("Query: $line");
-      print_error("Error: " . implode(", ", $this->pdo->errorInfo()));
+      print("Error: " . implode(", ", $this->pdo->errorInfo()));
     }
   }
 }
 
-print_notice("Database initialization completed.");
+print("Database initialization completed.");