diff --git a/src/printer_tree.c b/src/printer_tree.c
index a49b84c..c0a1a11 100644
--- a/src/printer_tree.c
+++ b/src/printer_tree.c
@@ -93,6 +93,7 @@
 #include "common.h"
 #include "compat.h"
 #include "out_internal.h"
+#include "printer_schema.h"
 #include "tree_schema_internal.h"
 #include "xpath.h"