diff --git a/src/lib-storage/list/Makefile.am b/src/lib-storage/list/Makefile.am
index 7998c7217f..58ba0d719c 100644
--- a/src/lib-storage/list/Makefile.am
+++ b/src/lib-storage/list/Makefile.am
@@ -33,6 +33,7 @@ headers = \
 	mailbox-list-index.h \
 	mailbox-list-index-storage.h \
 	mailbox-list-index-sync.h \
+	mailbox-list-iter-private.h \
 	mailbox-list-maildir.h \
 	mailbox-list-notify-tree.h \
 	mailbox-list-subscriptions.h \
diff --git a/src/lib-storage/list/mailbox-list-iter-private.h b/src/lib-storage/list/mailbox-list-iter-private.h
new file mode 100644
index 0000000000..4856432db8
--- /dev/null
+++ b/src/lib-storage/list/mailbox-list-iter-private.h
@@ -0,0 +1,23 @@
+#ifndef MAILBOX_LIST_ITER_PRIVATE_H
+#define MAILBOX_LIST_ITER_PRIVATE_H
+
+#include "mailbox-list-iter.h"
+
+struct autocreate_box {
+	const char *name;
+	const struct mailbox_settings *set;
+	enum mailbox_info_flags flags;
+	bool child_listed;
+};
+
+ARRAY_DEFINE_TYPE(mailbox_settings, struct mailbox_settings *);
+struct mailbox_list_autocreate_iterate_context {
+	unsigned int idx;
+	struct mailbox_info new_info;
+	ARRAY(struct autocreate_box) boxes;
+	ARRAY_TYPE(mailbox_settings) box_sets;
+	ARRAY_TYPE(mailbox_settings) all_ns_box_sets;
+	bool listing_autoboxes:1;
+};
+
+#endif
diff --git a/src/lib-storage/list/mailbox-list-iter.c b/src/lib-storage/list/mailbox-list-iter.c
index e2258d6983..e6ac9e23f1 100644
--- a/src/lib-storage/list/mailbox-list-iter.c
+++ b/src/lib-storage/list/mailbox-list-iter.c
@@ -7,6 +7,7 @@
 #include "mailbox-tree.h"
 #include "mailbox-list-subscriptions.h"
 #include "mailbox-list-private.h"
+#include "mailbox-list-iter-private.h"
 
 enum autocreate_match_result {
 	/* list contains the mailbox */
@@ -17,23 +18,6 @@ enum autocreate_match_result {
 	AUTOCREATE_MATCH_RESULT_PARENT		= 0x04
 };
 
-struct autocreate_box {
-	const char *name;
-	const struct mailbox_settings *set;
-	enum mailbox_info_flags flags;
-	bool child_listed;
-};
-
-ARRAY_DEFINE_TYPE(mailbox_settings, struct mailbox_settings *);
-struct mailbox_list_autocreate_iterate_context {
-	unsigned int idx;
-	struct mailbox_info new_info;
-	ARRAY(struct autocreate_box) boxes;
-	ARRAY_TYPE(mailbox_settings) box_sets;
-	ARRAY_TYPE(mailbox_settings) all_ns_box_sets;
-	bool listing_autoboxes:1;
-};
-
 struct ns_list_iterate_context {
 	struct mailbox_list_iterate_context ctx;
 	struct mailbox_list_iterate_context *backend_ctx;