diff --git a/cache.h b/cache.h
index 5b690b80a1..1188289774 100644
--- a/cache.h
+++ b/cache.h
@@ -312,10 +312,6 @@ typedef int (*must_prefetch_predicate)(const struct cache_entry *);
 void prefetch_cache_entries(const struct index_state *istate,
 			    must_prefetch_predicate must_prefetch);
 
-#ifdef USE_THE_INDEX_VARIABLE
-extern struct index_state the_index;
-#endif
-
 /* Initialize and use the cache information */
 struct lock_file;
 int do_read_index(struct index_state *istate, const char *path,
diff --git a/repository.h b/repository.h
index 655a95026d..1cb314721c 100644
--- a/repository.h
+++ b/repository.h
@@ -170,6 +170,9 @@ struct repository {
 };
 
 extern struct repository *the_repository;
+#ifdef USE_THE_INDEX_VARIABLE
+extern struct index_state the_index;
+#endif
 
 /*
  * Define a custom repository layout. Any field can be NULL, which
diff --git a/t/helper/test-dump-split-index.c b/t/helper/test-dump-split-index.c
index d1badd7112..63fde9157c 100644
--- a/t/helper/test-dump-split-index.c
+++ b/t/helper/test-dump-split-index.c
@@ -2,6 +2,7 @@
 #include "test-tool.h"
 #include "cache.h"
 #include "hex.h"
+#include "repository.h"
 #include "setup.h"
 #include "split-index.h"
 #include "ewah/ewok.h"