--- src/structs.h.orig	2021-11-16 12:12:25 +0000
+++ src/structs.h	2021-11-16 12:13:51 +0000
@@ -1526,7 +1526,7 @@
 {
     typval_T	di_tv;		// type and value of the variable
     char_u	di_flags;	// DI_FLAGS_ flags (only used for variable)
-    char_u	di_key[1];	// key (actually longer!)
+    char_u	di_key[10];	// key (actually longer!)
 };
 typedef struct dictitem_S dictitem_T;