diff --git a/src/libsysprof-capture/sysprof-capture-reader.c b/src/libsysprof-capture/sysprof-capture-reader.c
index c22d3bbf..5f609e2e 100644
--- a/src/libsysprof-capture/sysprof-capture-reader.c
+++ b/src/libsysprof-capture/sysprof-capture-reader.c
@@ -898,6 +898,9 @@ sysprof_capture_reader_save_as (SysprofCaptureReader  *self,
       to_write -= written;
     }
 
+  if (self->filename == NULL)
+    self->filename = g_strdup (filename);
+
   close (fd);
 
   return TRUE;