diff --git a/nixos/modules/services/databases/mysql.nix b/nixos/modules/services/databases/mysql.nix
index 4b2e83e71e20..7fcc423b4c91 100644
--- a/nixos/modules/services/databases/mysql.nix
+++ b/nixos/modules/services/databases/mysql.nix
@@ -337,6 +337,12 @@ in
 
     environment.etc."my.cnf".source = cfg.configFile;
 
+    # The mysql_install_db binary will try to adjust the permissions, but fail to do so with a permission
+    # denied error in some circumstances. Setting the permissions manually with tmpfiles is a workaround.
+    systemd.tmpfiles.rules = [
+      "d ${cfg.dataDir} 0755 ${cfg.user} ${cfg.group} - -"
+    ];
+
     systemd.services.mysql = {
       description = "MySQL Server";