diff --git a/meson.build b/meson.build
index 0adcb30..6f68902 100644
--- a/meson.build
+++ b/meson.build
@@ -49,6 +49,14 @@
     meson.project_name(),
 )
 threads = dependency('threads')
+if cpp.has_header('valijson/validator.hpp')
+    valijson = declare_dependency()
+else
+    subproject('valijson', required: false)
+    valijson = declare_dependency(
+        include_directories: 'subprojects/valijson/include'
+    )
+endif
 
 install_data('blacklist.json')