diff --git a/libs/freetdm/src/include/private/ftdm_core.h b/libs/freetdm/src/include/private/ftdm_core.h
index 8f149318b3..95f34b4dd2 100644
--- a/libs/freetdm/src/include/private/ftdm_core.h
+++ b/libs/freetdm/src/include/private/ftdm_core.h
@@ -117,6 +117,7 @@
 #include "ftdm_buffer.h"
 #include "ftdm_threadmutex.h"
 #include "ftdm_sched.h"
+#include "ftdm_call_utils.h"
 
 #ifdef __cplusplus
 extern "C" {