diff --git a/src/meson.build b/src/meson.build
index 47fcd33..a064f14 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -57,6 +57,7 @@
   'pinned.cpp',
   'raw.cpp',
   'signal.cpp',
+  'str/buf.cpp',
   'str/cat.cpp',
   'str/cexpr.cpp',
   'str/maps.cpp',