diff --git a/src/version.c b/src/version.c
index 9db5ad3b0..cbe988b1c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4413,
 /**/
     4412,
 /**/
diff --git a/src/vim9execute.c b/src/vim9execute.c
index d2c7d5daa..3c23ad411 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -3553,6 +3553,12 @@ exec_instructions(ectx_T *ectx)
 		    {
 			ufunc = find_func(funcref->fr_func_name, FALSE);
 		    }
+		    if (ufunc == NULL)
+		    {
+			SOURCING_LNUM = iptr->isn_lnum;
+			iemsg("ufunc unexpectedly NULL for FUNCREF");
+			goto theend;
+		    }
 		    if (fill_partial_and_closure(pt, ufunc, ectx) == FAIL)
 			goto theend;
 		    tv = STACK_TV_BOT(0);