diff --git a/src/eval.c b/src/eval.c
index db6ef9d..7708796 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -292,13 +292,12 @@
 #define VV_RO		2	/* read-only */
 #define VV_RO_SBX	4	/* read-only in the sandbox */
 
-#define VV_NAME(s, t)	s, {{t, 0, {0}}, 0, {0}}, {0}
+#define VV_NAME(s, t)	s, {{t, 0, {0}}, 0, {0}}
 
 static struct vimvar
 {
     char	*vv_name;	/* name of variable, without v: */
-    dictitem_T	vv_di;		/* value and name for key */
-    char	vv_filler[16];	/* space for LONGEST name below!!! */
+    dictitem16_T vv_di;		/* value and name for key (max 16 chars!) */
     char	vv_flags;	/* VV_COMPAT, VV_RO, VV_RO_SBX */
 } vimvars[VV_LEN] =
 {
diff --git a/src/structs.h b/src/structs.h
index 97eae57..abfe6cd 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1221,6 +1221,15 @@
 };
 typedef struct dictitem_S dictitem_T;
 
+/* A dictitem with a 16 character key (plus NUL). */
+struct dictitem16_S
+{
+    typval_T	di_tv;		/* type and value of the variable */
+    char_u	di_flags;	/* flags (only used for variable) */
+    char_u	di_key[17];	/* key */
+};
+typedef struct dictitem16_S dictitem16_T;
+
 #define DI_FLAGS_RO	1  /* "di_flags" value: read-only variable */
 #define DI_FLAGS_RO_SBX 2  /* "di_flags" value: read-only in the sandbox */
 #define DI_FLAGS_FIX	4  /* "di_flags" value: fixed: no :unlet or remove() */
diff --git a/src/version.c b/src/version.c
index 95e2cba..c929eaf 100644
--- a/src/version.c
+++ b/src/version.c
@@ -749,6 +749,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1648,
+/**/
     1647,
 /**/
     1646,