diff --git a/src/mod/applications/mod_fax/mod_fax.c b/src/mod/applications/mod_fax/mod_fax.c
index 517c86f41a..8a31fc979d 100644
--- a/src/mod/applications/mod_fax/mod_fax.c
+++ b/src/mod/applications/mod_fax/mod_fax.c
@@ -33,6 +33,8 @@
  */
 
 #include <switch.h>
+
+#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES
 #include <spandsp.h>
 #include <spandsp/version.h>