diff --git a/cache.h b/cache.h
index 4d04aecb0f..7ee3748ce1 100644
--- a/cache.h
+++ b/cache.h
@@ -597,6 +597,7 @@ extern int daemonize(void);
 /* Initialize and use the cache information */
 struct lock_file;
 extern int read_index(struct index_state *);
+extern void preload_index(struct index_state *, const struct pathspec *pathspec);
 extern int read_index_preload(struct index_state *, const struct pathspec *pathspec);
 extern int do_read_index(struct index_state *istate, const char *path,
 			 int must_exist); /* for testting only! */
diff --git a/preload-index.c b/preload-index.c
index 3b51d49904..354d1df0db 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -7,8 +7,7 @@
 #include "fsmonitor.h"
 
 #ifdef NO_PTHREADS
-static void preload_index(struct index_state *index,
-			  const struct pathspec *pathspec)
+void preload_index(struct index_state *index, const struct pathspec *pathspec)
 {
 	; /* nothing */
 }
@@ -73,8 +72,7 @@ static void *preload_thread(void *_data)
 	return NULL;
 }
 
-static void preload_index(struct index_state *index,
-			  const struct pathspec *pathspec)
+void preload_index(struct index_state *index, const struct pathspec *pathspec)
 {
 	int threads, i, work, offset;
 	struct thread_data data[MAX_PARALLEL];