diff --git a/libs/openzap/src/zap_io.c b/libs/openzap/src/zap_io.c
index 8721bdc82d..720bd9da24 100644
--- a/libs/openzap/src/zap_io.c
+++ b/libs/openzap/src/zap_io.c
@@ -249,6 +249,7 @@ zap_status_t zap_span_close_all(void)
 				zap_mutex_destroy(&span->channels[j].mutex);
 				zap_buffer_destroy(&span->channels[j].digit_buffer);
 				zap_buffer_destroy(&span->channels[j].dtmf_buffer);
+				zap_buffer_destroy(&span->channels[j].fsk_buffer);
 			}
 		}