--- a/src/ipfilter.c
+++ b/src/ipfilter.c
@@ -146,7 +146,7 @@
 				snprintf(msgstr, 60,
 					 "Invalid protocol input at or near token \"%s\"",
 					 bptr);
-				tui_error(ANYKEY_MSG, msgstr);
+				tui_error(ANYKEY_MSG, "%s", msgstr);
 				doagain = 1;
 			} else
 				doagain = 0;
