diff --git a/lib/files/filesystem.php b/lib/files/filesystem.php
index d6ebe7d629a6d90e00332e7179f242de678c1f79..4281ebba99d1c1ddf0331865c7d21f90de04c757 100644
--- a/lib/files/filesystem.php
+++ b/lib/files/filesystem.php
@@ -31,8 +31,9 @@
 namespace OC\Files;
 
 use OC\Files\Storage\Loader;
-const FREE_SPACE_UNKNOWN = -2;
-const FREE_SPACE_UNLIMITED = -3;
+const SPACE_NOT_COMPUTED = -1;
+const SPACE_UNKNOWN = -2;
+const SPACE_UNLIMITED = -3;
 
 class Filesystem {
 	/**
diff --git a/lib/files/storage/common.php b/lib/files/storage/common.php
index 3da13ac4df05306165b9f4a1e74908f468fcf7eb..8cd978f5b4d25259ccde1d83afbf946061fb462f 100644
--- a/lib/files/storage/common.php
+++ b/lib/files/storage/common.php
@@ -366,6 +366,6 @@ abstract class Common implements \OC\Files\Storage\Storage {
 	 * @return int
 	 */
 	public function free_space($path) {
-		return \OC\Files\FREE_SPACE_UNKNOWN;
+		return \OC\Files\SPACE_UNKNOWN;
 	}
 }
diff --git a/lib/files/storage/local.php b/lib/files/storage/local.php
index b08fd73ce1977cd41d1b1e9d51f7f47715bd7080..5209fabc30ad0ac6a4adfa665220e7ee61d9bd73 100644
--- a/lib/files/storage/local.php
+++ b/lib/files/storage/local.php
@@ -265,7 +265,7 @@ if (\OC_Util::runningOnWindows()) {
 		public function free_space($path) {
 			$space = @disk_free_space($this->datadir . $path);
 			if ($space === false) {
-				return \OC\Files\FREE_SPACE_UNKNOWN;
+				return \OC\Files\SPACE_UNKNOWN;
 			}
 			return $space;
 		}