diff --git a/cache.h b/cache.h
index 88d3b92d2e..fa5a9e523e 100644
--- a/cache.h
+++ b/cache.h
@@ -110,7 +110,6 @@ struct ondisk_cache_entry {
 };
 
 struct cache_entry {
-	struct cache_entry *next;
 	unsigned int ce_ctime;
 	unsigned int ce_mtime;
 	unsigned int ce_dev;
@@ -121,6 +120,7 @@ struct cache_entry {
 	unsigned int ce_size;
 	unsigned int ce_flags;
 	unsigned char sha1[20];
+	struct cache_entry *next;
 	char name[FLEX_ARRAY]; /* more */
 };
 
@@ -137,6 +137,22 @@ struct cache_entry {
 #define CE_HASHED    (0x100000)
 #define CE_UNHASHED  (0x200000)
 
+/*
+ * Copy the sha1 and stat state of a cache entry from one to
+ * another. But we never change the name, or the hash state!
+ */
+#define CE_STATE_MASK (CE_HASHED | CE_UNHASHED)
+static inline void copy_cache_entry(struct cache_entry *dst, struct cache_entry *src)
+{
+	unsigned int state = dst->ce_flags & CE_STATE_MASK;
+
+	/* Don't copy hash chain and name */
+	memcpy(dst, src, offsetof(struct cache_entry, next));
+
+	/* Restore the hash state */
+	dst->ce_flags = (dst->ce_flags & ~CE_STATE_MASK) | state;
+}
+
 /*
  * We don't actually *remove* it, we can just mark it invalid so that
  * we won't find it in lookups.
diff --git a/unpack-trees.c b/unpack-trees.c
index ec558f9005..07c4c28a5a 100644
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -590,7 +590,7 @@ static int merged_entry(struct cache_entry *merge, struct cache_entry *old,
 		 * a match.
 		 */
 		if (same(old, merge)) {
-			memcpy(merge, old, offsetof(struct cache_entry, name));
+			copy_cache_entry(merge, old);
 		} else {
 			verify_uptodate(old, o);
 			invalidate_ce_path(old);