diff --git a/src/vim9compile.c b/src/vim9compile.c
index 40411c4..d7c7c8b 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -1024,9 +1024,11 @@
     isn->isn_arg.ufunc.cuf_argcount = argcount;
 
     stack->ga_len -= argcount; // drop the arguments
-
-    // drop the funcref/partial, get back the return value
-    ((type_T **)stack->ga_data)[stack->ga_len - 1] = &t_any;
+    if (ga_grow(stack, 1) == FAIL)
+	return FAIL;
+    // add return value
+    ((type_T **)stack->ga_data)[stack->ga_len] = &t_any;
+    ++stack->ga_len;
 
     return OK;
 }