diff --git a/changes/fmt_addr b/changes/fmt_addr
new file mode 100644
index 0000000000..b88c9e1bf4
--- /dev/null
+++ b/changes/fmt_addr
@@ -0,0 +1,4 @@
+  o Minor bugfixes:
+    - When unable to format an address as a string, report its value
+      as "???" rather than reusing the last formatted address. Bugfix
+      on 0.2.1.5-alpha.
diff --git a/src/common/address.c b/src/common/address.c
index d0c2d5e15c..26a59e923e 100644
--- a/src/common/address.c
+++ b/src/common/address.c
@@ -958,8 +958,10 @@ fmt_addr(const tor_addr_t *addr)
 {
   static char buf[TOR_ADDR_BUF_LEN];
   if (!addr) return "<null>";
-  tor_addr_to_str(buf, addr, sizeof(buf), 0);
-  return buf;
+  if (tor_addr_to_str(buf, addr, sizeof(buf), 0))
+    return buf;
+  else
+    return "???";
 }
 
 /** Like fmt_addr(), but takes <b>addr</b> as a host-order IPv4