diff --git a/caching/cache_restore.cc b/caching/cache_restore.cc
index 62c4ea6..7e64d4c 100644
--- a/caching/cache_restore.cc
+++ b/caching/cache_restore.cc
@@ -18,16 +18,6 @@ using namespace std;
 //----------------------------------------------------------------
 
 namespace {
-	void check_file_exists(string const &file) {
-		struct stat info;
-		int r = ::stat(file.c_str(), &info);
-		if (r)
-			throw runtime_error("Couldn't stat file");
-
-		if (!S_ISREG(info.st_mode))
-			throw runtime_error("Not a regular file");
-	}
-
 	int restore(string const &xml_file, string const &dev) {
 		try {
 			block_manager<>::ptr bm = open_bm(dev, block_io<>::READ_ONLY);
diff --git a/persistent-data/file_utils.cc b/persistent-data/file_utils.cc
index e5fef3f..a96aec7 100644
--- a/persistent-data/file_utils.cc
+++ b/persistent-data/file_utils.cc
@@ -54,4 +54,15 @@ persistent_data::open_bm(std::string const &dev_path, block_io<>::mode m)
 	return block_manager<>::ptr(new block_manager<>(dev_path, nr_blocks, 1, m));
 }
 
+void
+persistent_data::check_file_exists(string const &file) {
+	struct stat info;
+	int r = ::stat(file.c_str(), &info);
+	if (r)
+		throw runtime_error("Couldn't stat file");
+
+	if (!S_ISREG(info.st_mode))
+		throw runtime_error("Not a regular file");
+}
+
 //----------------------------------------------------------------
diff --git a/persistent-data/file_utils.h b/persistent-data/file_utils.h
index c2d2d81..be1e492 100644
--- a/persistent-data/file_utils.h
+++ b/persistent-data/file_utils.h
@@ -3,11 +3,16 @@
 
 #include "persistent-data/block.h"
 
+#include <string>
+
 //----------------------------------------------------------------
 
+// FIXME: move to a different unit
 namespace persistent_data {
 	persistent_data::block_address get_nr_blocks(string const &path);
 	block_manager<>::ptr open_bm(std::string const &dev_path, block_io<>::mode m);
+
+	void check_file_exists(std::string const &file);
 }
 
 //----------------------------------------------------------------