diff --git a/src/buffer.c b/src/buffer.c
index 2983ca9..e2732de 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -2344,6 +2344,7 @@
     clear_string_option(&buf->b_p_tc);
 #ifdef FEAT_EVAL
     clear_string_option(&buf->b_p_tfu);
+    free_callback(&buf->b_tfu_cb);
 #endif
     clear_string_option(&buf->b_p_dict);
     clear_string_option(&buf->b_p_tsr);