diff --git a/apps/app_fax.c b/apps/app_fax.c
index c0621f5bb8..8c0b645ec8 100644
--- a/apps/app_fax.c
+++ b/apps/app_fax.c
@@ -516,6 +516,7 @@ static int transmit_audio(fax_session *s)
 		}
 
 		ast_frfree(inf);
+		inf = NULL;
 	}
 
 	ast_debug(1, "Loop finished, res=%d\n", res);