diff --git a/common/xfdesktop-common.c b/common/xfdesktop-common.c
index 1cba4ec..f20af1a 100644
--- a/common/xfdesktop-common.c
+++ b/common/xfdesktop-common.c
@@ -270,7 +270,7 @@ xfdesktop_image_file_is_valid(const gchar *filename)
     int fd;
     gboolean size_read = FALSE;
     guchar buf[4096];
-    gsize len;
+    gssize len;
 
     g_return_val_if_fail(filename, FALSE);