diff --git a/src/vim9compile.c b/src/vim9compile.c
index fceb481..8d6c139 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -6802,6 +6802,8 @@
     else if (add_def_function(ufunc) == FAIL)
 	return FAIL;
 
+    ufunc->uf_def_status = UF_COMPILING;
+
     CLEAR_FIELD(cctx);
     cctx.ctx_ufunc = ufunc;
     cctx.ctx_lnum = -1;