diff --git a/install/dist/lib/debian60.lib.php b/install/dist/lib/debian60.lib.php
index d76a45c2d30155d3952516383bea6ab8fb77defa..981e6cff92a70216656435bddb10a393f01dca54 100644
--- a/install/dist/lib/debian60.lib.php
+++ b/install/dist/lib/debian60.lib.php
@@ -110,6 +110,9 @@ class installer extends installer_base {
 			}
 			// Copy custom config file
 			if(is_file($conf['ispconfig_install_dir'].'/server/conf-custom/install/dovecot_custom.conf.master')) {
+				if(!@is_dir($config_dir . '/conf.d')) {
+					mkdir($config_dir . '/conf.d');
+				}
 				copy($conf['ispconfig_install_dir'].'/server/conf-custom/install/dovecot_custom.conf.master', $config_dir.'/conf.d/99-ispconfig-custom-config.conf');
 			}
 			replaceLine($config_dir.'/'.$configfile, 'postmaster_address = postmaster@example.com', 'postmaster_address = postmaster@'.$conf['hostname'], 1, 0);
diff --git a/install/lib/installer_base.lib.php b/install/lib/installer_base.lib.php
index 6de768f7e5ca7594d863efc721f013209c290bf4..56178263131382e2aca8eb19d4e250b67c4de3a9 100644
--- a/install/lib/installer_base.lib.php
+++ b/install/lib/installer_base.lib.php
@@ -1536,6 +1536,9 @@ class installer_base {
 			}
 			// Copy custom config file
 			if(is_file($conf['ispconfig_install_dir'].'/server/conf-custom/install/dovecot_custom.conf.master')) {
+				if(!@is_dir($config_dir . '/conf.d')) {
+					mkdir($config_dir . '/conf.d');
+				}
 				copy($conf['ispconfig_install_dir'].'/server/conf-custom/install/dovecot_custom.conf.master', $config_dir.'/conf.d/99-ispconfig-custom-config.conf');
 			}
 			replaceLine($config_dir.'/'.$configfile, 'postmaster_address = postmaster@example.com', 'postmaster_address = postmaster@'.$conf['hostname'], 1, 0);