diff --git a/libs/spandsp/src/msvc/spandsp.h b/libs/spandsp/src/msvc/spandsp.h
index deb146884e..95ee8bf11b 100644
--- a/libs/spandsp/src/msvc/spandsp.h
+++ b/libs/spandsp/src/msvc/spandsp.h
@@ -99,6 +99,7 @@
 #include <spandsp/v18.h>
 #include <spandsp/v42.h>
 #include <spandsp/v42bis.h>
+#include <spandsp/timezone.h>
 #include <spandsp/t4_rx.h>
 #include <spandsp/t4_tx.h>
 #include <spandsp/t4_t6_decode.h>