diff --git a/tiifetch.tcl b/tiifetch.tcl
index 790d58d..dfa299f 100755
--- a/tiifetch.tcl
+++ b/tiifetch.tcl
@@ -207,8 +207,10 @@ proc fetchiidb {url echos dbdir dolog} {
     set line [string trim $line]
     # detect if the line is related to echo name or message ID 
     if {[string first "." $line] eq -1} { # message ID
-      if {$curecho ne ""} {
-        dict lappend echomap $curecho $line
+      if {[string length $line] == 20} { # filter out invalid IDs
+        if {$curecho ne ""} {
+          dict lappend echomap $curecho $line
+        }
       }
     } else { # echo name
       set curecho $line