diff --git a/rerere.c b/rerere.c
index e0862e2778..473d32a5cd 100644
--- a/rerere.c
+++ b/rerere.c
@@ -568,7 +568,7 @@ static int find_conflict(struct string_list *conflict)
 {
 	int i;
 	if (read_cache() < 0)
-		return error("Could not read index");
+		return error("index file corrupt");
 
 	for (i = 0; i < active_nr;) {
 		int conflict_type;
@@ -601,7 +601,7 @@ int rerere_remaining(struct string_list *merge_rr)
 	if (setup_rerere(merge_rr, RERERE_READONLY))
 		return 0;
 	if (read_cache() < 0)
-		return error("Could not read index");
+		return error("index file corrupt");
 
 	for (i = 0; i < active_nr;) {
 		int conflict_type;
@@ -1103,7 +1103,7 @@ int rerere_forget(struct pathspec *pathspec)
 	struct string_list merge_rr = STRING_LIST_INIT_DUP;
 
 	if (read_cache() < 0)
-		return error("Could not read index");
+		return error("index file corrupt");
 
 	fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
 	if (fd < 0)