diff --git a/add-interactive.c b/add-interactive.c
index de877ca052..99f7dc3b0d 100644
--- a/add-interactive.c
+++ b/add-interactive.c
@@ -5,6 +5,7 @@
 #include "diffcore.h"
 #include "gettext.h"
 #include "hex.h"
+#include "preload-index.h"
 #include "revision.h"
 #include "refs.h"
 #include "string-list.h"
diff --git a/builtin/add.c b/builtin/add.c
index 36ddbb159b..8397be4f8d 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -17,6 +17,7 @@
 #include "cache-tree.h"
 #include "run-command.h"
 #include "parse-options.h"
+#include "preload-index.h"
 #include "diff.h"
 #include "diffcore.h"
 #include "revision.h"
diff --git a/builtin/am.c b/builtin/am.c
index 5c83f2e003..0d8f46f8d5 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -29,6 +29,7 @@
 #include "unpack-trees.h"
 #include "branch.h"
 #include "object-name.h"
+#include "preload-index.h"
 #include "sequencer.h"
 #include "revision.h"
 #include "merge-recursive.h"
diff --git a/builtin/checkout.c b/builtin/checkout.c
index d6765c9dbd..2d72a742d9 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -20,6 +20,7 @@
 #include "object-name.h"
 #include "object-store.h"
 #include "parse-options.h"
+#include "preload-index.h"
 #include "refs.h"
 #include "remote.h"
 #include "resolve-undo.h"
diff --git a/builtin/commit.c b/builtin/commit.c
index ee296e5ec6..877955e894 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -30,6 +30,7 @@
 #include "utf8.h"
 #include "object-name.h"
 #include "parse-options.h"
+#include "preload-index.h"
 #include "string-list.h"
 #include "rerere.h"
 #include "unpack-trees.h"
diff --git a/builtin/diff-files.c b/builtin/diff-files.c
index 360464e6ef..3ac175264d 100644
--- a/builtin/diff-files.c
+++ b/builtin/diff-files.c
@@ -8,6 +8,7 @@
 #include "diff.h"
 #include "diff-merges.h"
 #include "commit.h"
+#include "preload-index.h"
 #include "revision.h"
 #include "builtin.h"
 #include "submodule.h"
diff --git a/builtin/diff-index.c b/builtin/diff-index.c
index b9a19bb7d3..9b98db2e77 100644
--- a/builtin/diff-index.c
+++ b/builtin/diff-index.c
@@ -3,6 +3,7 @@
 #include "diff.h"
 #include "diff-merges.h"
 #include "commit.h"
+#include "preload-index.h"
 #include "revision.h"
 #include "builtin.h"
 #include "setup.h"
diff --git a/builtin/diff.c b/builtin/diff.c
index 7b64659fe7..967550739a 100644
--- a/builtin/diff.c
+++ b/builtin/diff.c
@@ -16,6 +16,7 @@
 #include "diff.h"
 #include "diff-merges.h"
 #include "diffcore.h"
+#include "preload-index.h"
 #include "revision.h"
 #include "log-tree.h"
 #include "builtin.h"
diff --git a/builtin/stash.c b/builtin/stash.c
index 8856ac6d5c..06527ee847 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -17,6 +17,7 @@
 #include "run-command.h"
 #include "dir.h"
 #include "entry.h"
+#include "preload-index.h"
 #include "rerere.h"
 #include "revision.h"
 #include "setup.h"
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
index fa30959535..7b201d76a8 100644
--- a/builtin/submodule--helper.c
+++ b/builtin/submodule--helper.c
@@ -11,6 +11,7 @@
 #include "parse-options.h"
 #include "quote.h"
 #include "pathspec.h"
+#include "preload-index.h"
 #include "dir.h"
 #include "setup.h"
 #include "sparse-index.h"
diff --git a/cache.h b/cache.h
index 79daaa166b..b79802a463 100644
--- a/cache.h
+++ b/cache.h
@@ -318,9 +318,6 @@ extern struct index_state the_index;
 
 /* Initialize and use the cache information */
 struct lock_file;
-void preload_index(struct index_state *index,
-		   const struct pathspec *pathspec,
-		   unsigned int refresh_flags);
 int do_read_index(struct index_state *istate, const char *path,
 		  int must_exist); /* for testting only! */
 int read_index_from(struct index_state *, const char *path,
diff --git a/preload-index.c b/preload-index.c
index 7a26b08c21..c26739debf 100644
--- a/preload-index.c
+++ b/preload-index.c
@@ -8,6 +8,7 @@
 #include "fsmonitor.h"
 #include "gettext.h"
 #include "config.h"
+#include "preload-index.h"
 #include "progress.h"
 #include "thread-utils.h"
 #include "repository.h"
diff --git a/preload-index.h b/preload-index.h
new file mode 100644
index 0000000000..251b1ed88e
--- /dev/null
+++ b/preload-index.h
@@ -0,0 +1,15 @@
+#ifndef PRELOAD_INDEX_H
+#define PRELOAD_INDEX_H
+
+struct index_state;
+struct pathspec;
+struct repository;
+
+void preload_index(struct index_state *index,
+		   const struct pathspec *pathspec,
+		   unsigned int refresh_flags);
+int repo_read_index_preload(struct repository *,
+			    const struct pathspec *pathspec,
+			    unsigned refresh_flags);
+
+#endif /* PRELOAD_INDEX_H */
diff --git a/read-cache.c b/read-cache.c
index e1016ae031..3fad839fb6 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -27,6 +27,7 @@
 #include "mem-pool.h"
 #include "name-hash.h"
 #include "object-name.h"
+#include "preload-index.h"
 #include "resolve-undo.h"
 #include "revision.h"
 #include "run-command.h"
diff --git a/repository.h b/repository.h
index 74ae26635a..655a95026d 100644
--- a/repository.h
+++ b/repository.h
@@ -221,9 +221,6 @@ int repo_hold_locked_index(struct repository *repo,
 			   struct lock_file *lf,
 			   int flags);
 
-int repo_read_index_preload(struct repository *,
-			    const struct pathspec *pathspec,
-			    unsigned refresh_flags);
 int repo_read_index_unmerged(struct repository *);
 /*
  * Opportunistically update the index but do not complain if we can't.