diff --git a/builtin/repack.c b/builtin/repack.c
index a176de2f85..8b7dfd043a 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -117,6 +117,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 {
 	struct {
 		const char *name;
+		unsigned optional:1;
 	} exts[] = {
 		{".pack"},
 		{".idx"},
@@ -323,6 +324,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
 			char *fname, *fname_old;
 			struct stat statbuffer;
+			int exists = 0;
 			fname = mkpathdup("%s/pack-%s%s",
 					packdir, item->string, exts[ext].name);
 			fname_old = mkpathdup("%s-%s%s",
@@ -330,9 +332,12 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 			if (!stat(fname_old, &statbuffer)) {
 				statbuffer.st_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
 				chmod(fname_old, statbuffer.st_mode);
+				exists = 1;
+			}
+			if (exists || !exts[ext].optional) {
+				if (rename(fname_old, fname))
+					die_errno(_("renaming '%s' failed"), fname_old);
 			}
-			if (rename(fname_old, fname))
-				die_errno(_("renaming '%s' failed"), fname_old);
 			free(fname);
 			free(fname_old);
 		}