diff --git a/lib/com_err/lex.l b/lib/com_err/lex.l
index 1eff51d2c..780c117a5 100644
--- a/lib/com_err/lex.l
+++ b/lib/com_err/lex.l
@@ -112,7 +112,7 @@ error_message (char *format, ...)
      va_list args;
 
      va_start (args, format);
-     fprintf (stderr, "%s:%d: ", filename, lineno);
+     fprintf (stderr, "%s:%d:", filename, lineno);
      vfprintf (stderr, format, args);
      va_end (args);
      numerror++;