diff --git a/rzip.c b/rzip.c
index 774d4d6..7793257 100644
--- a/rzip.c
+++ b/rzip.c
@@ -766,8 +766,8 @@ void rzip_fd(int fd_in, int fd_out)
 	/* Check if there's enough free space on the device chosen to fit the
 	 * compressed file, based on the compressed file being as large as the
 	 * uncompressed file. */
-	if (unlikely(fstatvfs(fd_in, &fbuf)))
-		fatal("Failed to fstatvfs in decompress_file\n");
+	if (unlikely(fstatvfs(fd_out, &fbuf)))
+		fatal("Failed to fstatvfs in compress_file\n");
 	free_space = fbuf.f_bsize * fbuf.f_bavail;
 	if (free_space < control.st_size) {
 		if (FORCE_REPLACE)